I. SOCIAL ASPECTSWilliam Petersen
II. ECONOMIC ASPECTSErinley Thomas
In its most general sense “migration” is ordinarily defined as the relatively permanent movement of persons over a significant distance. But this definition, or any paraphrase of it, merely begins to delimit the subject, for the exact meaning of the most important terms (“permanent,” “significant”) is still to be specified. A person who goes to another country and remains there for the rest of his life, we say, is a migrant; and one who pays a two-hour visit to the nearest town is not. Between these two extremes lies a bewildering array of intermediate instances, which can only partly be distinguished by more or less arbitrary criteria (Lacroix 1949).
Permanence of movement
What should be the minimum duration of stay that differentiates a migration from a visit? With respect to international migration, the recommendation of the United Nations (and the practice of a number of countries) is to define removal for one year or more as “permanent,” and thus as migration, while a stay for a shorter period is classified as a visit. Note that the data reflect not behavior but statements about future behavior; and persons have been known to lie to immigration officials or to change their minds.
This kind of ambiguity often makes it difficult to interpret migration statistics. For example, according to a critical analysis of United States im-migration statistics (Kuznets & Rubin 1954, table 7), during the height of the mass immigration of 1890-1910 about forty per cent of the foreign-born returned. Conclusions from uncorrected immigration data, therefore, are likely to be grossly inaccurate. Remigrants—those who leave their country of origin for a period and then return to it—ordinarily differ from the emigrants who remain abroad, but not necessarily according to any consistent pattern. Particularly during an economic depression, some immigrants left the new country when they lost their jobs (Berthoff 1953, p. 73). Sometimes, on the contrary, it was the relatively successful that returned, either to find wives (Borrie 1954) or to retire. The rise of nationalism in the old country often attracted back some of the incompletely assimilated migrants (Saloutos 1956). A small percentage of the subsidized emigrants to Australia and Canada have returned to Britain, and the especially careful studies made of these groups are largely inconclusive (Appleyard 1962a; 1962b; Richmond 1966). Almost by definition, remigrants are less able to acculturate to their new environment than immigrants who remain there, but few valid generalizations can be added to that truism.
The ambiguity pertains also to the definition of internal migrants (Hamilton 1961; Taeuber 1961). Particularly in a federal country like the United States, “permanence” of movement is defined, in effect, by laws stipulating the meaning of domicile with respect to marriage and divorce, suffrage, and other prerogatives reserved to “bona fide residents.” Surveys by the U.S. Bureau of the Census show that each year approximately one person in five moves to a new residence (compare Wilber 1963). However, according to a detailed analysis of one particular community (Goldstein 1954), a sizable proportion of this large percentage is made up of persons who move more than once during a year and who are atypical also in other ways. A study of repeated migration in Denmark suggests that the phenomenon is not restricted to any one country (Goldstein 1964).
More generally, when one speaks of migratory birds, or migrant laborers, or nomads, the connotation is not of a permanent move from one area to another, but rather of a permanently migratory way of life, which often means a cyclical movement within a more or less definite area. Nomads (the word derives from the Greek for pasturing) typically follow their herds back and forth over a region delimited either by natural boundaries or by neighbors sufficiently powerful to repel incursions. Similarly, agricultural laborers often move with the growing season, and shepherds (in what is termed transhumance) alternate between high mountain pastureland in the summer and lowlands in the winter. Commutation, the daily “journey to work” (Liepmann 1944), constitutes a similar cycle within a smaller compass. One must not accept the common notion that such a separation of place of residence from place of work is peculiar to modern industrial societies. Many of the burghers of ancient Athens, fourteenth-century London, and preindustrial cities generally were part-time agriculturists (Petersen 1961, pp. 348-353). In many presently underdeveloped countries, particularly India and Pakistan, a peasant who migrates to the city often leaves his family in the village, to which he therefore returns periodically. In Africa south of the Sahara the temporary separation of male industrial or mine workers from village life has been institutionalized into the standard pattern (Mitchell 1961). In sum, whether short-term re movals should be included in migration depends on the purpose of the statistics being collected. Thus, no particular specification of the duration of stay suits all purposes, and each analyst has to adapt the available data to his needs as best he can.
The meaning of migration also varies according to how a “significant” distance is defined. The word derives from the Latin migrare, to change one’s residence, but by current definitions it means rather to change one’s community. A person who moves from one home to another in the same neighborhood, and who therefore retains the same social framework, is not deemed a migrant.
If we regard a nation as a community, then by this criterion all international movements are included under the rubric “migration.” Partly because of this rationale, partly because the two sets of statistics are separately collected, the distinction between international and internal migration sets the framework of most analyses. It is worth emphasizing, therefore, that in a general discussion of the phenomenon the distinction is more or less irrelevant. Not only do some types of migration fall outside of this dichotomy (prehistoric wanderings, for instance), but some of the most important and interesting characteristics of migrants apply whether or not they cross an international border (labor mobility, urbanization, migratory selection, acculturation, etc.). Moreover, there are often greater cultural differences within the boundaries of a nation than between nations.
In practice, geographical distance is generally taken as a rough measure of whether the migrant crosses into another community. Thus, the U.S. Bureau of the Census divides the mobile population between “movers,” who have changed their residence within a single county, and “migrants,” who have crossed a county line, and it subdivides the latter category according to whether they move within a single state, to an adjacent state, or to a nonadjacent state. This kind of classification passes over the fact that a farmer who moves to a town in the same county probably changes his way of life more than one who crosses the nation but remains a farmer. To take a more striking example, the tens of thousands of refugees who fled from East to West Berlin have traversed the most significant boundary line in Europe while remaining within the confines of a single city.
Models of migration
It is reasonable to suppose that the number of migrants within any area homogeneous with respect to all the other factors that affect the propensity to migrate will be inversely related to the distance covered. One can express this relation in an equation, as follows: M = aX/D&, where M stands for the number of migrants, D for the distance over the shortest transportation route, and X for any other factor that is thought to be relevant; a and b are constants, usually set at unity. In one version of this equation, the so-called P1P2/D hypothesis, the populations of the end points of the movement are taken as the X factor (Zipf 1949). Another variation is the familiar proposition that the number of persons going a given distance is directly proportional to the number of employment opportunities at that distance and inversely proportional to the number of intervening opportunities (Stouffer 1940). When “opportunities” were defined operationally as the number of in-migrants, the hypothesis could be validated in a number of instances. According to a detailed comparison of the two, Stouffer’s formulation is better than Zipf’s, since, in effect, measuring opportunities corrects the total population figures for the amount of unemployment in the two areas (Anderson 1955). (For other models, see Lovgren 1956; Thomlinson 1961; Heide 1963; Tabah & Cataldi 1963.)
A proposition about migration between only two points is too simplistic a unit, however, to be a useful building block for more elaborate theories. These have in general started from other premises. An important example is the three-volume study Population Redistribution and Economic Growth: United States, 1870-1950 (Kuznets 1957-1964), in which the available data concerning the regional distribution of the developing national economy and data concerning internal migration are combined into a unified analysis of the interaction between the two.
This kind of analysis is not limited to migration within a single country. A shorter work in the same broad perspective analyzes the post-1945 migration to Switzerland (Mayer 1966). According to several studies of the transatlantic movement, if conditions in the home country build up a propensity to emigrate, the volume, direction, and timing of the movement are set largely by the business cycle in the receiving country (e.g., D. S. Thomas 1941). A later work, however, challenged this interpretation and placed more emphasis on the unity of “the Atlantic economy” and the importance of “push” factors (B. Thomas 1954).
In most of the supposedly general models of migration, it is presumed that movement is generated mainly by economic forces. This may not always be a reasonable postulate. Whether the correlation between business cycles and migratory movements is positive or negative, for example, sometimes depends only on how broadly the study is conceived. While the rise of Europe’s urban-industrial civilization brought a great increase in population and thus a pressure to emigrate, it also resulted in a general rise in the level of aspiration. Young men who were better off than their fathers were nonetheless dissatisfied, and many sought to better themselves overseas. Thus, it may be true to say that for certain periods the dominant motivation of emigrants from particular countries was economic, even though these countries had, by and large, far better conditions than those from which very few persons left. This paradox is not limited to economic factors: religious oppression, or the infringement of political liberty, was often a motive for European emigration, but before the rise of modern totalitarianism those who left came predominantly from precisely those countries least marked by such stigmata. An increasing propensity to emigrate spread east and south from northwest Europe, together with democratic institutions and religious tolerance. The anomaly that those who emigrated “because” of persecution tended to come from countries where there was less of it than elsewhere can be analyzed only by separating personal motivation from social causation. According to a recent survey of British emigrants’ motives, they tended to rationalize their general feeling of insecurity and inadequacy into more specific economic factors (Appleyard 1964).
At least in the United States, internal migration is also less motivated by economic factors than is usually assumed. At one time, the U.S. Bureau of the Census asked a sample of migrants who had moved during one year why they had moved (“Postwar Migration” . . . 1947; compare “Reasons for Moving . . .” 1966, which showed similar responses). Only 22.6 per cent said it was to take a job or to look for work. Family migration constituted 61.7 per cent (i.e., moving with the head of the family or to join him, moving because of a change in marital status); 6.4 per cent said it was because of housing problems. Health, climate, education, and miscellaneous motives accounted for the remaining respondents. This conclusion has been generally validated by the few other studies made of internal migrants’ motivation (e.g., Rossi 1955).
That migration is both related to economic trends and yet not, in any simple sense, caused by them, should not occasion any surprise. The same is true of many other complex social phenomena. It would be no contribution to substitute for purely economic causes a list of other “factors,” ranging from the spirit of adventure to the development of transportation facilities; nor would it be a great improvement to divide such a list between circumstances at home that repel and those abroad that attract, that is, between “push” and “pull” factors. Given a sedentary population and an inducement to leave home, typically some persons go and some stay behind. Push and pull factors, in short, do not exert their force equally. The self-selection by which migrants differentiate themselves from the sedentary population is called migratory selection (or, by some authors, selective migration). An analysis of this process can afford a better understanding of why a migration takes place.
It is a valuable extension of the Stouffer-Zipf generalization, for example, to go beyond the counting of heads and differentiate among the types of migrants. It is not sufficient, even in an analysis restricted to economically motivated migrations, to posit job opportunities in general: potential migrants with specific skills go to places where there are openings specifically for them. Thus, among white migrants within the United States, those seeking higher-status positions generally have to move greater distances than those with lower levels of skill. And some job-seeking migrants are also strongly motivated by noneconomic factors: among American Negroes important reasons for moving have been to get out of the rural South (hence the high rate of urbanization), and prefer-ably to get out of the South altogether (hence the shift to the North and West). Negroes, therefore, move greater distances than would be expected from the level of skill in the jobs that they typically seek (Rose 1958; compare Stub 1962; Taeuber & Taeuber 1965).
It is possible to analyze migratory selection by a number of demographic and social characteristics in addition to occupation and race; and although the conclusions from different studies vary widely, some tentative generalizations are possible (D. S. Thomas 1938; Petersen 1961, pp. 592-603). In both internal and international movements adolescents and young adults predominate; for not only do the young adapt more easily, but since they are close to the beginning of their working life, they can more readily take advantage of new opportunities. It is feasible, therefore, to analyze migration by cohorts (Eldridge 1964).
One can argue a priori that either the less or the more intelligent will tend to migrate: since the more intelligent will have succeeded at home, the less intelligent will seek their fortunes elsewhere; on the other hand, the more intelligent will respond first to any stimulus to migrate, while the duller will remain behind. Various studies have seemed to validate one or the other of these propositions. It is possible to reconcile the contradiction by postulating that a selection by intelligence is in fact one by actual or potential occupational level (Hofstee 1952; compare Lee 1966). Thus, since urban occupations are generally more demanding, ruralurban movements typically select the more intelligent. This is not true, however, of agriculturists who move to manual jobs in the cities, such as Negroes in the United States (D. S. Thomas 1938, pp. 111-121), or in general of migrants who make no substantial change in vocational level.
Effects on populations
For the two areas concerned, migratory selection determines the significance of the movement almost as much as the number of migrants. Consider the ramifications of what can be taken as the most fundamental question in migration theory: If X persons leave country A and migrate to country B, what changes take place in the size of the two populations (Petersen 1955, chapter 9)? The common-sense answer, that country A is decreased and country B is increased by X, is true only in the short run. If the typically young migrants have their children in their new country, its fertility rate may go up, while that of their native country goes down. Since the remaining population of country A will then be older on the average, its death rate may go up, while that of country B goes down. In short, after a generation the transfer of X persons will in fact amount to X plus a certain proportion based on the migration’s effects on the population structures, and rates of population growth, of the two countries.
At a third level of analysis, however, this increment, and indeed X itself, may be canceled out. For Malthus, thus, emigration was a slight palliative, a partial and temporary expedient, with no permanent effect on population size (Malthus 1798, book 3, chapter 7). This is likely to be true of any country where the mortality of infants and children is high (so that emigration would reduce the mortality slightly), or where marriages and conceptions are put off because of economic pressure (so that a lesser pressure, the consequence of emigration, would result in a higher fertility). If one includes such indirect effects, the change in the population of the immigration country is also difficult to estimate. Immigration to the United States, for example, accelerated urbanization and industrialization; and these changes, in turn, increased the upward social mobility of the native population and thus tended to accelerate the secular decline of the birth rate.
In sum, even the simplest question—How many persons migrated?—cannot be fully answered merely by counting heads. Unlike mortality and fertility, migration has no biological dimension: it cannot be analyzed, even in preliminary terms, independently of its cultural context. Accordingly, there are no “laws” of migration in the sense of universal generalizations; the highest level of abstraction possible is the contrast of various types of migrants (Heberle 1955).
In a study of migrants to Aberdeen—that is, of movement within the single country of Scotland over only a few years—it was found useful to classify respondents into a number of types. These included professionals seeking careers, young persons seeking education, workers taking specific jobs, casual workers looking for employment, former commuters moving for greater convenience, family migrants joining heads of families, and return migrants (Illsley et al. 1963, pp. 238-240). The conclusions to be drawn differed for these various classes.
If this is so for movements within a relatively homogeneous area, then it is manifestly the case for migration in its most general terms, encompassing the whole world and all of human history. In constructing a general typology, one should begin by choosing the criteria by which the types are to be distinguished (Petersen 1964, pp. 271-290). Perhaps the most fundamental is the distinction between innovating migrants, who move in order to achieve the new, and conservative migrants, who move in response to a change in their circumstances, hoping by migrating to retain their way of life in another locus. Within each of these two broad classes, one can distinguish types of migration according to the force impelling the movement. An ecological push results in what might be termed a primitive migration—not a wandering of primitive tribes as such, but one dependent on a people’s inability to cope with natural forces. When the activating agent is the state or some equivalent institution, the movement is forced or impelled migration, depending on whether the prospective migrants retain some power to decide whether to leave or not. A movement of adventurous pioneers, deviant religious or political groups, or similar individually motivated persons can aptly be termed free migration. Its importance is not in its size, which is never large, but in the example it sets for others. If the ensuing flow develops into a broad stream, an established pattern for whole social classes, an example of collective behavior, we speak of mass migration, similar to what has been termed “chain migration” (MacDonald & MacDonald 1964). Then individual motivations become correspondingly less important—indeed, the individuals involved may not be able to give a rational account of their decision to migrate. The motives they ascribe are likely to be trivial or, more probably, the generalities that they think are expected (Hansen 1940a, pp. 77–78).
Uses of typological method
The value of such a typology is in its utility: Does it help in solving analytical problems? The typology suggests, first of all, that migratory selection ranges along a continuum, from total migration at one extreme (food gatherers or nomads) to total nonmigration at the other. Intermediate instances, moreover, cannot be arranged along a single dimension. Sometimes it is the age or the sex or the occupation of the potential migrant that is relevant, but if an ethnic or social minority leaves to escape persecution or is shipped off to concentration camps, then the only pertinent characteristic is how the state defines “Jew” or “kulak,” for example.
For more than a century various governments, concerned about the depopulation (real or supposed) of villages, have sought measures to counteract it. It would increase understanding of the process merely to ask whether this is a conservative or an innovating migration: Do these agriculturists want better conditions within their present way of life, or do they move to cities for the sake of urban amenities? Perhaps the most useful distinction in the typology is that between mass migration and all other types, for it emphasizes the fact that the nineteenth-century exodus from Europe does not constitute the whole of the phenomenon. When this type of migration declined after World War i, largely because of new political limitations imposed by both emigration and immigration countries, this was very often interpreted as marking the end of significant human migration altogether (e.g., Forsyth 1942). It was rather, in large part, a change to neomercantilist migration, in which the welfare of the national state becomes the main criterion for judging whether the movement is desirable and in which state agencies foster or impede, force or prevent, the migration. The “natural” right of the passportless person to move about has been sup-planted by the “natural” right of the state to control that movement (Petersen 1955, chapter 1).
In the present age of total wars and totalitarian regimes, political motivations have set not only “Europe on the move” (Kulischer 1948) but also, partly as reverberations of European influences, much of the rest of the world. To take a notable example, the partition of British India into the nations of India and Pakistan was accompanied by one of the largest migrations in human history, in part induced by terrorists on both sides, in part arranged under state auspices. Many analysts prefer to omit this type of movement from their purview. In a United Nations publication, for example, international migration is defined as “the noncoerced migrations, which constitute the great majority of all migratory movements in normal times, and which are closely related to economic and social factors. . . . Specifically, ’migration’ excludes population transfers, . . . deportations, refugee movements, and the movements of ’displaced persons’” (United Nations 1953, p. 98). That an international body which includes some of the states most responsible for forced migrations should exclude them from its demographic analyses is understandable; but there is no reason why independent scholars should accept this arbitrary and misleading definition.
The number of refugees in the world today depends of course on how that term is defined. Data on “refugees” are compiled mainly by the various agencies set up to aid them, and the resultant totals considerably understate the number of persons who have migrated because of political stress and sought refuge elsewhere. The major world-wide agency, the office of the U.N. High Commissioner for Refugees, has a narrowly restricted prime mandate: to assist persons who do not want to return to their country because of actual or feared racial, religious, or political persecution; and it may also extend its “good offices” to certain other limited categories. This definition does not include several numerically important classes of uprooted peoples: (1) those who have fled from local political disturbances but remain within the boundaries of the same state; (2) those who are forcibly moved about within the boundaries of a single state (see, for example, Conquest 1960); (3) those who have been forced to “return” to what is now defined as “their” country, after having lived “abroad” sometimes for generations. Thousands of refugees remain as hard-core cases from World War i, the Spanish Civil War, and World War n. It has been estimated, probably conservatively, that about forty million persons became refugees in the dozen years following 1945 (Rees 1957); the implication of the figure can be better grasped when it is recalled that the usual estimate for the total migration from all of Europe from 1800 to 1950 is only one and a half times as large, that is, sixty million.
Anderson, Theodore R. 1955 Intermetropolitan Migration: A Comparison of the Hypotheses of Zipf and Stouffer. American Sociological Review 20:287–291.
Apple Yard, R. T. 1962 a The Return Movement of United Kingdom Migrants From Australia. Population Studies 15:214–225.
Appleyard, R. T. 1962£ Determinants of Return Migration: A Socio-economic Study of United Kingdom Migrants Who Returned From Australia. Economic Record 38:352–368.
Appleyard, R. T. 1964 British Emigration to Australia. London: Weidenfeld & Nicolson.
Berthoff, Rowland T. 1953 British Immigrants in Industrial America: 1790-1950. Cambridge, Mass.: Harvard Univ. Press.
Borrie, Wilfrid D. 1954 Italians and Germans in Australia: A Study of Assimilation. Melbourne: Cheshire.
Canada, Department of Citizenship And Immigration 1961 Citizenship, Immigration, and Ethnic Groups in Canada: A Bibliography of Research, 1920-1958. Ottawa: Queen’s Printer.
Conquest, Robert 1960 The Soviet Deportation of Nationalities. New York: St. Martins.
Eldridge, Hope T. 1964 A Cohort Approach to the Analysis of Migration Differentials. Demography I : 212–219.
Forsyth, William D. 1942 The Myth of Open Spaces: Australian, British and World Trends of Population and Migration. Melbourne Univ. Press.
Goldstein, Sidney 1954 Repeated Migration as a Factor in High Mobility Rates. American Sociological Review 19:536–541.
Goldstein, Sidney 1961 The Norristown Study: An Experiment in Interdisciplinary Research Training. Philadelphia: Univ. of Pennsylvania Press.
Goldstein, Sidney 1964 The Extent of Repeated Migration: An Analysis Based on the Danish Population Register. Journal of the American Statistical Association 59:1121–1132.
Hamilton, C. Horace 1961 Some Problems of Method in Internal Migration Research. Population Index 27: 297–307.
Hansen, Marcus L. 1940 a The Immigrant in American History. Cambridge, Mass.: Harvard Univ. Press. → A paperback edition was published in 1964 by Harper.
Hansen, Marcus L. 1940£The Atlantic Migration: 1607–1860. Cambridge, Mass.: Harvard Univ. Press. → A paperback edition was published in 1961 by Harper.
Haskett, Richard C. 1956 An Introductory Bibliography for the History of American Immigration: 1607-1955. Pages 85–295 in Stanley J. Tracy (editor), A Report on World Population Migrations. Washington: George Washington Univ.
Heberle, Rudolf 1955 Theorie der Wanderungen. Schmollers Jahrbuch fur Gesetzgebung, Verwaltung und Volkswirtschaft im Deutschen Reiche 75:1–23.
Heide, H. TER 1963 Migration Models and Their Significance for Population Forecasts. Milbank Memorial Fund Quarterly 41:56–76.
Hofstee, E. W. 1952 Some Remarks on Selective Migration. Research Group for European Migration Problems, Publications, No. 7. The Hague: Nijhoff.
Hutchinson, Edward P. 1956n Immigrants and Their Children: 1850-1950. New York: Wiley.
Illsley, Raymond; Finlayson, Angela; and Thompson, Barbara 1963 The Motivation and Characteristics of Internal Migrants: A Socio-medical Study of Young Migrants in Scotland. Milbank Memorial Fund Quarterly 41:115–143, 217–248.
International Economic Association 1958 Economics of International Migration. Edited by Brinley Thomas. New York: St. Martins; London: Macmillan.
International Labor Office 1928-1929 Migration Laws and Treaties. Vol. 1–3. Studies and Reports, Series O, No. 3. Geneva: The Office.
International Labor Office 1959 International Migration: 1945-1957. Studies and Reports, New Series, No. 54. Geneva: The Office.
Kirk, Dudley 1946 Europe’s Population in the Interwar Years. Geneva: League of Nations.
Kulischer, Eugene M. 1948 Europe on the Move: War and Population Changes, 1917-1947. New York: Columbia Univ. Press.
Kuznets, Simon (editor) 1957-1964 Population Redistribution and Economic Growth: United States, 1870-1950. Memoirs, Nos. 45, 51, 61. Philadelphia: American Philosophical Society.
Kuznets, Simon; and Rubin, Ernest 1954 Immigration and the Foreign Born. National Bureau of Economic Research, Occasional Paper No. 46. New York: The Bureau.
Lacroix, Max 1949 Problems of Collection and Comparison of Migration Statistics. Pages 71–105 in Milbank Memorial Fund, Problems in the Collection and Comparability of International Statistics. New York: The Fund.
Lavell, C. B.; and Schmidt, Wilson E. 1956 An Annotated Bibliography on the Demographic, Economic and Sociological Aspects of Immigration. Pages 296-449 in Stanley J. Tracy (editor), A Report on World Population Migrations. Washington: George Washington Univ.
Lee, Everett S. 1966 A Theory of Migration. Demography 3:47–57.
Lee, Everett S.; and Lee, Anne S. 1960 Internal Migration Statistics for the United States. Journal of the American Statistical Association 55:664–697.
Liepmann, Kate K. (1944) 1945 The Journey to Work: Its Significance for Industrial and Community Life. London: Routledge.
Lovgren, Esse 1956 The Geographical Mobility of Labour: A Study of Migrations. Geografiska annaler 38:344–394.
Macdonald, John S.; and Macdonald, Leatrice D. 1964 Chain Migration, Ethnic Neighborhood Formation, and Social Networks. Milbank Memorial Fund Quarterly 42:82–97.
Malthus, Thomas R. (1798) 1958 An Essay on Population. 2 vols. New York: Dutton. → First published as An Essay on the Principle of Population. A paperback edition was published in 1963 by Irwin. MAYER, KURT B. 1966 The Impact of Postwar Immigration on the Demographic and Social Structure of Switzerland. Demography 3:68–89.
Milbank Memorial Fund 1947 Postwar Problems of Migration. New York: The Fund.
Milbank Memorial Fund 1958 Selected Studies of Migration Since World War II. New York: The Fund.
Mitchell, J. Clyde 1961 Wage Labour and African Population Movements in Central Africa. Pages 193-248 in K. M. Barbour and R. M. Prothero (editors), Essays on African Population. London: Routledge. National Bureau of Economic Research 1929-1931 International Migrations. Edited by Walter F. Willcox. 2 vols. New York: The Bureau. → Volume 1: Statistics, compiled on behalf of the International Labour Office, Geneva, with introduction and notes by Imre Ferenczi. Volume 2:Interpretations, by a group of scholars in different countries.
Petersen, William 1955 Planned Migration: The Social Determinants of the Dutch-Canadian Movement. Berkeley: Univ. of California Press.
Petersen, William 1961 Population. New York: Macmillan.
Petersen, William 1964 The Politics of Population. Garden City, N.Y.: Doubleday.
Postwar Migration and Its Causes in the United States: August, 1945, to October, 1946. 1947 U.S. Bureau of the Census, Current Population Reports Series P–20, No. 4.
Reasons for Moving: March 1962 to March 1963. 1966 U.S. Bureau of the Census, Current Population Reports. Series P–20, No. 154.
Rees, Elfan 1957 Century of the Homeless Man. International Conciliation 515:193–254.
Richmond, A. H. 1966 Demographic and Family Characteristics of British Immigrants Returning From Canada. International Migration 4:21–26.
Rose, Arnold M. 1958 Distance of Migration and Socioeconomic Status of Migrants. American Sociological Review 23:420–423.
Rosenfield, Harry N. 1957 Historical Research as a Tool for Immigration Policy. American Jewish Historical Society, Publications 46:341–365.
Rossi, Peter H. 1955 Why Families Move: A Study in the Social Psychology of Urban Residential Mobility. Glencoe, III.: Free Press.
Saloutos, Theodore 1956 They Remember America: The Story of the Repatriated Greek-Americans. Berkeley: Univ. of California Press.
Shimm, Melvin G. (editor) 1956 Immigration. Law and Contemporary Problems 21, no. 2.
Shyock, Henry S. 1964 Population Mobility Within the United States. Univ. of Chicago, Community and Family Study Center.
STOUFFER, SAMUEL A. 1940 Intervening Opportunities: A Theory Relating Mobility and Distance. American Sociological Review 5:845–867.
STUB, HOLGER R. 1962 The Occupational Characteristics of Migrants to Duluth: A Retest of Rose’s Hypothesis. American Sociological Review 27:87–90.
Tabah, Leon; and Cataldi, Alberto 1963 Effets d’une immigration dans quelques populations modeles. Population 18:683–696.
Taeuber, Karl E. 1961 Duration-of-residence Analysis of Internal Migration in the United States. Milbank Memorial Fund Quarterly 39:116–131.
Taeuber, Karl E.; and Taeuber Alma F. 1965 The Changing Character of Negro Migration. American Journal of Sociology 70:429–441.
Thomas, Brinley 1954 Migration and Economic Growth: A Study of Great Britain and the Atlantic Economy. Cambridge Univ. Press.
Thomas, Brinley 1961 International Migration and Economic Development: A Trend Report and Bibliography. Paris: Unesco.
Thomas, Dorothy S. 1938 Research Memorandum on Migration Differentials. New York: Social Science Research Council.
Thomas, Dorothy S. 1941 Social and Economic Aspects of Swedish Population Movements: 1750-1933. New York: Macmillan.
Thomlinson, Ralph 1961 A Model for Migration Analysis. Journal of the American Statistical Association 56:675–686.
Tracy, Stanley J. (editor) 1956 A Report on World Population Migrations. Washington: George Washington Univ.
United Nations, Department of Economic And Social Affairs 1955 Analytical Bibliography of International Migration Statistics, Selected Countries: 1925-1950. U.N. Bureau of Social Affairs, Population Studies, No. 24. New York: United Nations.
United Nations, Department of Social Affairs 1949 Problems of Migration Statistics. Population Studies, No. 5. New York: United Nations.
United Nations, Department of Social Affairs 1953 The Determinants and Consequences of Population Trends: A Summary of the Findings of Studies on the Relationships Between Population Changes and Economic and Social Conditions. Population Studies, No.17. New York: United Nations.
U.S. Congress, House, Committee ON The Judiciary 1950 The Displaced Persons Analytical Bibliography. House Report No. 1687. Washington: Government Printing Office.
Wilber, George L. 1963 Migration Expectancy in the United States. Journal of the American Statistical Association 58:444–453.
Wilber, George L.; and Rogers, Tommy W. 1965 Internal Migration in the United States, 1958 to 1964: A List of References. Sociology and Rural Life Series, No. 15. Unpublished manuscript, Mississippi State Univ., Agricultural Experiment Station.
ZIPF, GEORGE K. 1949 Human Behavior and the Principle of Least Effort: An Introduction to Human Ecology. Reading, Mass.: Addison-Wesley. → See especially “The Factor of Distance,” pages 386–409.
Zubrzycki, Jerzy 1960 Immigrants in Australia: A Demographic Survey Based Upon the 1954 Census. 2 vols. Melbourne Univ. Press. → Volume 2 is a statistical supplement.
This article is mainly concerned with international migration, which may be defined, in the strict sense, as a permanent movement of people, of their own free will, from one sovereign country to another. Transfers of this kind, however, account for only a small part of the redistribution of world population in the last three centuries. A comprehensive view of international migration must therefore include forced as well as free move ments, and temporary as well as permanent movements. It is also necessary to distinguish between intercontinental and intracontinental transfers.
Free and forced movements
Up to the beginning of the nineteenth century there were hardly any statistical records of international migration. Nevertheless, it is possible to indicate the main orders of magnitude. The first great Atlantic migration was the traffic in African slaves. It is estimated that over ten million slaves were transported to America between 1619 and 1776 and that 3.4 million of them went to the English colonies in America. The trade was initiated by the Portuguese and the Dutch. Britain also took part, beginning in the 1660s, mainly through the Royal African Company, which existed from 1672 to 1752. The plantation economies producing sugar in the West Indies, tobacco in Virginia, and rice and indigo in South Carolina entailed a growing demand for slave labor from Africa. In the West Indies white immigration was replaced by black on one island after another, until slaves constituted about four-fifths of the population.
In contrast, the white migration across the Atlantic in the seventeenth and eighteenth centuries was comparatively small. In the seventeenth century about 250,000 left the British Isles for the New World, and in the eighteenth century the out-flow was perhaps 1,500,000, of whom about half a million were Ulster Presbyterians. An indication of the volume of Spanish emigration to the New World is given by the fact that 150,000 were recorded as having embarked at the port of Seville between 1509 and 1740, but this is a serious underestimate. The only other prominent group of trans-Atlantic migrants up to 1800 was the 200,000 Germans estimated to have left for America.
The nineteenth century was the great age of mass migration from Europe across the Atlantic of people who went of their own free will, and most of what we know about the economic and social determinants and consequences of international migration is based on the experience of that remarkable period. Between 1846 and 1932 about 52 million people left Europe for oversea destinations. When this redistribution was over, one-eleventh of the population of the world were people of European origin living outside Europe.
One of the most somber features of our time is that while there has been a sharp decline in free international mobility, the relative scale of forced transfers is reminiscent of the eighteenth century. The world picture has been dominated by movements of refugees, as shown by the following rough estimates. The partition of India and Pakistan led to the expulsion of more than 18 million people from their homes. Other outstanding examples of inflows of refugees after World War n are West Germany, 12 million; Japan, 6.3 million; South Korea, 4 million; Hong Kong, 1.3 million; Israel, 1 million; Arab refugees from Palestine, 1 million. About 1.5 million refugees were settled overseas by the International Refugee Organisation and the Intergovernmental Committee for European Migration [see Refugees, article on World Problems]. This is only a partial account, for it is impossible to give estimates of the considerable forced movements which have taken place between countries controlled by the Soviet Union and China. Even this partial estimate of the international transfer of “political” migrants gives a total of 45 million for the ten years beginning in 1945. It is a sobering thought that the number of people expelled from one country to another in the decade after World War II was equal to the entire oversea emigration from Europe in the century ending in 1913.
Temporary and permanent movements
Of the large number of passengers who enter or leave any country in a given period, only a proportion are genuine migrants. Persons to be counted as migrants are those who move from one country to a permanent residence in another, and, in accordance with United Nations standards, the criterion generally adopted is a declared intention to stay in the receiving country for more than one year. Owing to the wide variety of methods used in different countries, it is not easy to obtain accurate statistics. It must be recognized, however, that much of the international mobility of labor which is of economic significance is of a temporary nature. This is particularly true on the European continent, where daily or weekly or seasonal movements over national frontiers occur on a considerable scale. For example, permanent immigration into Switzerland rose steadily from 1946 to 1957 and amounted to 690,000 workers for the period as a whole; during the same period there were 942,000 seasonal workers and 275,000 frontier workers. The net immigration for the period was, however, only 250,000; this demonstrates that a number of the aliens admitted as “permanent” immigrants (a great many being women) are in fact in the temporary category. On the American continent a similar case may be seen in the seasonal traffic across the border between Mexico and the United States.
Intercontinental and intracontinental movements
The distinction between intercontinental and intracontinental movements is illuminating when we are dealing with the phases in the migration of Europeans. With the exception of the movement of Russians into Asia, the story of the outpouring of Europe’s population is largely one of oversea settlement, and it is noteworthy that the migrations which have had the deepest and most enduring effects have been those which were transoceanic and intercontinental. When migrants cross an ocean, there are strict limits to what they can take with them; their traditions, ideals, techniques, and material belongings, when applied in a distant and strange environment, yield a pattern of life quite different from the one they left behind. There is something irrevocable about crossing an ocean. The political, economic, and racial configuration of the United States today is very much the out-come of three transoceanic migrations—the Pilgrim Fathers and their successors, the slaves from Africa, and the European masses in the nineteenth century.
When we consider shifts of population in Asia, we find that intercontinental movements are not significant, for a journey by sea has often meant merely a transfer from one part of the same continent to another. The abolition of slavery in the British colonies in the 1830s saw the beginning of an outflow from the Far East to the countries of America, Oceania, and Africa; and throughout the nineteenth century the recruitment of indentured laborers from India, China, and Japan was a characteristic feature. This species of intercontinental migration came to an end in the 1920s, and its place was taken by interregional movements which have had important demographic and social effects. The chief suppliers of intracontinental migrants have been China, India, Pakistan, Japan, and Korea; the main recipients have been Malaya, Ceylon, Burma, Indonesia, Thailand, Vietnam, Laos, Cambodia, British Borneo, the Philippines, and Manchuria. In most of these countries the immigrants have been mainly Chinese and Indians. In the Far East internal migration has been more important than transfers across national boundaries. For example, in Japan in the period 1920–1940 the net exodus from rural areas to urban areas amounted to 17.5 million persons. This was more than the entire increase in the population of Japan in this period, and it was ten times greater than the net emigration from the country.
The measurement of migration
Countries did not begin to keep records of genuine international migration until the big modern movements had passed their peak. For most of the nineteenth century the available statistics were by-products of acts or regulations introduced to achieve some other purpose. For example, in the United States and the United Kingdom, records of passenger movements were the results of acts passed to regulate shipping. In Britain, statistics began to be furnished under an act in 1803. But it was not until over a century later, in 1912, that the British Board of Trade decided to adopt a sta
|Table 1—Intercontinental migration, selected countries and periods (in thousands)|
|Country of||Period||Number of||Country of||Period||Number of|
|source: Adapted from carr-saunders 1936,p.49.|
|Austria and Hungary||1846-13932||5,196||Argentina||1856-1932||6,405|
|British Isles||1846-1932||18,020||British West Indies||1836-1932||1,587|
tistical classification which defined a migrant as a passenger who declares that he has lived for a year or more in one country and intends to remain for a year or more in another. Statistical tests have shown that, despite their obvious deficiencies, “. . . the Board of Trade statistics of aggregate net passenger movement are a surprisingly good measure of the course of total net emigration from the United Kingdom in the period ending in 1912” (Thomas 1954, p. 52). This would not hold good for recent times, because air travel has become important and Britain persists in not including air migrants in her statistics.
The primary data used by various countries to measure international migration can be grouped under six headings: those yielded by controls at ports, by transport contracts, by population registers, by control at land frontiers, by passports, and by coupons detached from certain documents. In North America, South America, Asia, and Africa the usual practice has been to base the records on controls at frontiers and ports; in Europe, however, countries have adopted one or another of the six systems. Each government has tended to organize its migration statistics in accordance with its own particular policy objectives, without any regard to the need for international comparability. The result has been a bewildering variety of definitions and classifications.
Valuable attempts have been made by the International Labor Office to point the way toward a common pattern (see, for example, International Labor Office 1932; 1952). In recent years the problem of improving migration statistics has been thoroughly explored by the United Nations. An inquiry in 1950 showed that only 16 out of 45 countries classified emigrants by country of future residence or destination and only 17 classified immigrants by country of last residence or origin, while only 16 distinguished between continental
|Table 2 – World population, by continent, in 1946 and 1957, and balance of intercontinental migration in the intervening period (in millions)|
|* Not available.|
|source: Adapted from International Labour Office 1959,p.304|
|Table 3 – Population growth and net migration for selected countries, 1946-1957 (in thousands)|
|ESTIMATED NET MIGRATION|
|Per cent||Per cent|
|Source: Adapted from International Labor Office 1959, pp. 308, 312.|
|United States||141,390||27,735 +2,200||+ 1.6||+8|
|New Zealand||1,660||351||+ 145||+8.7||+41|
and intercontinental immigrants and 10 between continental and intercontinental emigrants. For the demographer it was disconcerting that only 16 countries gave information on the marital status of migrants, and in nine of these countries this information was not combined with age grouping. As a result of the work of the Economic and Social Council of the United Nations, most of the known statistics have been set out in two comprehensive mono-graphs (United Nations, Bureau of Social Affairs 1953; 1958). These surveys cover 33 countries and include tables classifying migrants by occupation or industry, state of dependency, possession or nonpossession of a contract for employment, and, for the United States, Israel, and South Africa, the amount of money which immigrants bring in with them (for additional detailed information, see United Nations, Department of Economic and Social Affairs 1955).
Since progress in improving official sources on migration is inevitably a slow process, it is all the more necessary to check imperfect time series in the light of the more accurate population census data at decennial intervals. Thus, Kuznets and Rubin (1954) have compared the annual record of immigration into the United States over a long period with the estimates obtained from the census figures on resident foreign-born. Similarly, Keyfitz (1950) has drawn up a population balance sheet for Canada for the century 1851-1950, including the best possible estimates of immigration and emigration in each decade.
Some indications of the scale of intercontinental population movements from the middle of the nineteenth century to the middle of the twentieth can be found in tables 1-3.
Economic determinants of migration
The period 1840-1924 was in several respects unique in the history of migration. The evolution of the Atlantic economy in that era necessitated a considerable movement of population and capital from the Old World, which was relatively well endowed with these factors, to the New World, where they were relatively scarce. Over 45 million people crossed the ocean; the average rate of growth of population in each decade of the nineteenth century was 29 per cent in the United States, 34 per cent in Argentina, and 8 per cent in Europe. The world’s chief provider of capital was Great Britain; of her foreign investments of over $17,000 million in 1913, nearly 70 per cent were located in North America, South America, and Oceania.
The motives which led these millions of people to leave their homelands were infinitely varied; a lengthy catalogue of them would be full of human interest but would not provide an interpretation of the phenomenon. At certain times and in certain places the operative force was political oppression or religious persecution or eviction by tyrannical landlords or the threat of starvation or evasion of military service or the love of adventure or the lure of gold or the attraction of a new country with limitless opportunities. But what has to be explained is why the individual decisions of millions of people resulted in four major upswings with intervening downswings, with an average interval of 15 to 20 years from peak to peak, in oversea emigration from Europe. The emigration upswings took place in 1845-1854, 1863-1873, 1881-1888, and 1903-1913. There can be no possible doubt about the explanation of the first of these: its inception had nothing to do with demand conditions in the United States. Calamity struck in Ireland in 1845, when the potato crop failed and a terrible famine followed; and as if this were not enough, the landlords added to the horrors by violently evicting thousands of peasants from their homes. In another part of Europe, southwest Germany, in the years 1848-1854 a severe crisis in the rural areas (in addition to the prevailing political unrest) brought population pressure to a head, and the only solution was emigration. In that period, of the 2,796,000 European immigrants who landed in the United States, no less than 80 per cent came from Ireland and Germany—1,283,000 from Ireland and 939,000 from Germany. This was essentially a Malthusian evacuation; both its timing and its magnitude were determined by exogenous driving forces in two stricken areas of Europe.
The explanation of the subsequent fluctuations in migration lies in a complicated process of inter-action between the economies of the Old World and those of the countries of new settlement overseas. It is significant that when the receiving countries, notably the United States, Canada, and Australia, were absorbing immigrants on a large scale, they were also experiencing a long upswing in capital construction (such as railroads and housing), which is sensitive to population growth. When this cycle entered its downward phase, with both migration and capital imports dwindling, there was simultaneously an upsurge in capital construction in the United Kingdom, where the rural surplus was now absorbed in urban areas at home. This capital construction was financed by loanable funds which were no longer attracted abroad (Thomas 1954).
Thus, there was an inverse relation between long swings in population-sensitive capital formation in the United Kingdom and in the United States, and in the United Kingdom there was an inverse relation between external migration and internal migration. The mechanism of this inverse long swing between the United Kingdom and the United States can be seen most clearly in the period 1870-1913; it arose because a substantial part of total capital formation was sensitive to the rate of population growth and the rate of population growth was determined by the net migration balance. There are some grounds for thinking that the propensity to emigrate was in some way related to a cycle of births in Europe that caused a periodic recurrence of swollen numbers in the emigration age groups (Thomas 1954).
In the interwar period some of the basic trends of the pre-1913 era were reversed. The United States had become the world’s leading exporter of capital, and the Immigration Restriction Act of 1924 virtually closed the doors to further immigration except on a very modest scale. From the turn of the century, British settlement in Canada, Australia, New Zealand, and South Africa had been expanding, and British emigration to the Empire considered as a proportion of British emigration to the United States, which had been only 43 per cent in 1881-1900, had risen to 245 per cent by 1911-1913. After World War i Britain embarked on a substantial program of Empire settlement, and in the decade 1922-1931, 400,000 emigrants received financial support to enable them to settle in the overseas dominions. However, this outflow did not survive the world depression, which had such severe consequences that it actually reversed the world currents of migration. In 1932, 11 European countries of emigration received a net inward bal ance of 102,000 persons, and Argentina, Australia, New Zealand, the United States, and Uruguay together had a net outflow of 65,000 (International Labor Office 1932). The international migration picture had become a perverse caricature of its former self.
Changes since World War II
The factors determining the volume, quantity, and direction of international migration since World War II are quite different from what they were in the nineteenth century. Profound structural changes have taken place in the Atlantic economy, and they have had far-reaching effects on the pattern of world migration. It is necessary to distinguish between the years immediately after the war and the period beginning in 1952. The correspondence between international flows of people and of private capital, which was the outstanding feature of the nineteenth century, disappeared. In its place there emerged in the years 1945—1952 an international circular flow based on the immense net transfer of $33,800 million of public capital (government loans and grants) from the United States, $22,800 million of which went to Europe. This recovery program made it possible for the exhausted countries of Europe, particularly the United Kingdom, France, the Netherlands, and Belgium, to resume exports of people and capital to the oversea territories with which they had a special relationship. It facilitated the revival of migration and mobility of capital within the British Commonwealth and strengthened the purchasing power of the less developed parts of the world. Perhaps the most significant effect of the recovery program was its contribution to basic capital formation in western Europe. This contribution was the prelude to the remarkable upsurge in economic growth in the 1950s [seeForeignAid].
After 1952 a new balance of economic forces emerged. American economic aid to Europe ended, but the volume of military aid rose considerably and the amount of private investment by American firms in Europe greatly increased, until in 1959 for the first time the flow of new American funds for direct investment was larger in western Europe than in either Canada or Latin America. Rapid economic growth in western Europe has meant a remarkable increase in intracontinental migration and a continued decline in emigration to oversea countries. Net immigration into the European Economic Community amounted to 288,000 in 1960 and 421,000 in 1961. The latter figure was particularly large because of the repatriation of French and Belgian nationals from Africa. Looking at the separate countries, we find that in 1961 West Germany had a net inflow of 421,000 and France 150,000, whereas Italy had a net outflow of 164,000. Over the five years 1956-1960 the net outward migration from Italy to other European countries was at an annual average of 83,000, and emigration from Italy to oversea countries fell from 111,000 in 1956 to 48,000 in 1960. Intracontinental migration is increasing at the expense of the traditional European outflow to countries such as those of Latin America, and this is basically determined by the economic resurgence of western Europe and the consequent change in the economic balance within the Atlantic economy.
New determinants are also operating on other continents. The complex problems of migration on the African continent have been explored in a comprehensive study by the International Labor Office (1958). The spread of industrial development draws Africans long distances from their rural homes, but they are often prevented from becoming members of a settled work force. They find themselves suspended with the maximum of insecurity between the village to which they are attached and the harsh conditions of the industrial labor market. This can have disastrous social consequences: the countryside is denuded of a large part of its labor, family life is broken up, the social structure disintegrates, and there is neither economic nor social security. The General Conference of the International Labor Office in 1955 adopted a recommendation on the protection of migrants in underdeveloped countries which is clearly relevant to Africa.
Most underdeveloped countries are detrimentally affected by current trends in the migration of qualified personnel. In the nineteenth century, skilled manpower tended to accompany capital flows from advanced to less developed countries: in the modern world the bulk of private investment is a circulatory process within the rich sector, and there is a suction of skilled labor from the poorer countries into the more advanced. Of the 9,245 immigrant engineers admitted to the United States in 1953—1956, 50 per cent came from Europe, 25 per cent from Canada, and 22 per cent from “other countries,” which included a number in a low state of economic development. The same was true of natural scientists ([U.S.] National Science Foundation 1958). Unskilled labor is often complementary to skilled, and when there is a decline in the immigration of the latter into a developing country, as has occurred, e.g., in Latin America, the scope for the absorption of unskilled immigrants is automatically curtailed. Some of the international movements of relatively scarce human capital ten to widen the disparity between rates of economic growth in rich and poor countries. Such transfers could be on such a scale that some underdeveloped countries could never begin the process of growth. There seems to be a conflict here between the principle of freedom to migrate and the goal of reducing inequality. However, in assessing the economic effects of the migration of a factor of production, the relevant criterion is not marginal private productivity, but marginal social productivity. Judged by this criterion, some of the international migration of skill in the world today is perverse.
Impact on receiving countries
It used to be argued that immigration into the United States had not added to the American population because its effect had been counterbalanced by an induced decline in the fertility of native-born Americans (see, for instance, Walker 1891). This proposition has been disproved. Modern demographic analysis has demonstrated that the immigrations of the last century had hardly any net effect on the rate of natural increase of the native-born population in the receiving countries. It is estimated that in France between 1801 and 1936 net immigration was 3,960,000 and contributed only a third of the growth of population within the 1936 boundaries of the country during that period. The white population of the United States in 1790 was about 3.2 million; their descendants living in the United States in 1920 have been estimated at 41 million, and in the same year the number of descendants or survivors of immigrants since 1790 came to about 53 million. In that period net immigration into the United States was about 26.5 mil-lion (United Nations, Department of Social Affairs 1953, p. 139).
One of the most striking examples of mass im-migration in recent times is that into West Germany, which absorbed 12 million immigrants in 12 years after the war. Although this influx increased the population of West Germany by one-third, it failed to make up for the gaps in the demographic structure caused by war losses, since the immigrant population had suffered the same kinds of losses in the same age groups (International Labor Office 1959, pp. 27-28).
In recent years there has been a dramatic change of trend in the United Kingdom, a traditional country of emigration. Since 1958 there has been an appreciable net inward movement of migrants. This reversal of trend was caused by the substantial inflow of colored Commonwealth citizens, mainly from the West Indies, India, and Pakistan.
This led the government to introduce legislation to regulate Commonwealth immigration; the Commonwealth Immigrants Act came into force on July 1, 1962. Although the total number of colored people living in the United Kingdom is only about 1 per cent of the population, the newcomers have tended to cluster in certain places, and this has given rise to difficult social problems. This is part of a wider phenomenon—compare, for instance, the situation of the Puerto Ricans in the United States or the north Africans in France. Where poor, overpopulated countries have special relationships with advanced countries, it is natural that an overflow of population will take place so long as channels of mobility remain open.
Impact on sending countries
Mass emigration can in certain circumstances turn into a self-reinforcing process with profound long-run effects on the sending country. This arises from one of the most significant of migration differentials, the fact that the incidence of migration is particularly heavy in the age group 15-30. Given a substantial initial outflow, the sequel can be as follows. There is a decline in the marriage rate and consequently a fall in the size of the age group 0-5; but, since the rate of emigration among children is relatively low, the 0-5 age group becomes a relatively large group ten years later. It is a paradox that countries which are heavy losers through emigration seem to be liberally endowed with teen-agers. The process is self-perpetuating because, after a lag of about 15 years from the original thinning out of the 15-30 age group, the number entering the high emigration age group of 15-20 is relatively high in relation to the total population.
The influence of mass emigration on age composition in the sending country can be observed most strikingly in the case of Ireland, from which the total outflow from 1850 to 1911 was 4,191,000. By 1951, 30 per cent of the population were aged 45 and over, as compared with 16 per cent in 1841, and 11 per cent were 65 and over, as compared with 3 per cent in 1841. The experiences of Ire-land, Sweden, and Scotland show that substantial emigration tends to reduce the marriage rate, but we cannot be certain about the long-run effects on fertility. There can be little doubt that prolonged emigration helps to explain why there are so many spinsters in Ireland; however, the women who do get married have relatively large numbers of children. As to the death rate, the tendency is for the loss of good lives from the 15-35 age group through emigration to raise the average death rate in that group.
It is broadly agreed that assimilation is best regarded as a mutual process of integration. An American sociologist has well said that “. . . the United States has not assimilated the newcomer nor absorbed him. Our immigrant stock and our so-called ‘native’ stock have each integrated with the other. . . . It will be apparent that this concept of integration rests upon a belief in the importance of cultural differentiation within a framework of social unity. It recognizes the right of groups and individuals to be different so long as the differences do not lead to domination or disunity” (Borrie 1959, pp. 93-94). One of the difficulties of group settlement, e.g., in Latin America, is that there arises a conflict between the immediate interests of the migrant in his group and the long-run objective of cultural integration. Much benefit can be derived from the provision of instruction to the migrant before he has left his own country. The Intergovernmental Committee for European Migration has evolved effective means of selecting, educating, and pretraining European migrants, [SeeRefugees, article on AdjustmentAndAssimilation.]
Experts who have studied migration in Asia stress the importance of assimilation as a necessary condition of the diffusion of skills. In colonial regimes there was a tendency for skilled immigrants to remain a class apart, and they often sought to maintain the relative scarcity of their skill. The great need in Asian countries now is for the importation of skilled personnel who will assimilate easily and thereby facilitate the rapid spread of technical knowledge.
International migration no longer plays the role in economic growth that it did in the nineteenth century. Legislative restrictions, the changes in the economic determinants, and the population up-surge in different parts of the world have all tended to reduce the scale of movement. Countries which have been receiving a relatively large influx of migrants since World War II, e.g., Australia, will soon find that the rate of entry into the working population from the swollen lower age groups will make immigration on the old scale unnecessary. The international circulation of skilled manpower has become relatively more important, Intercontinental migrations have lost most of their significance and have been replaced by intracontinental movements.
Much more interdisciplinary research is needed into the problems of adjustment of immigrants, particularly where they are ethnically different from the population of the host country; the inter-action between external and internal migration; the relation between immigration and the incidence of mental health; the determinants of the rate of increase of immigrant groups in multiracial societies; and the economic and social consequences of the changing pattern of the international circulation of skilled manpower.
[Directly related are the entriesCapital, Human; Refugees. Other relevant material may be found inAssimilation; Population, article on Population Distribution; and in the biographies ofGiniand Kulischer.]
Borrie, Wilfrid D. et al. 1959 The Cultural Integration of Immigrants: A Survey Based Upon the Papers and Proceedings of the UNESCO Conference Held in Havana, April 1956 . . .With Case Studies. Paris: UNESCO.
Carr-Saunders, Alexander M. 1936 World Population: Past Growth and Present Trends. Oxford: Clarendon.
Eisenstadt, Shmuel N. (1954) 1955 The Absorption of Immigrants: Comparative Study Based Mainly on the Jewish Community in Palestine and the State of Israel. Glencoe, III.: Free Press.
Gini, Corrado 1946 Los efectos demográficos de las rnigraciones internacionales. Revista internacional de sociologia(Madrid)4:351–388.
International Economic Association 1958 Economics of International Migration: Proceedings of a Conference.Edited by Brinley Thomas. New York: St. Martins; London: Macmillan.
International Labor Office 1932 Statistics of Migration: Definitions-Methods-Classifications.Geneva: The Office.
International Labor Office 1952 International Classification of Occupations for Migration and Employment Placement. 2 vols. Geneva: The Office. → Volume 1: Occupational Tables, Codes and Definitions.Volume 2:Tables of Occupational Comparability: Major Occupational Groups 1 Through 6.
International Labor Office 1958 African Labour Survey.International Labour Organization Studies and Reports, New Series, No. 48,Geneva: The Office.
International Labor Office 1959 International Migration:1945–1957. International Labour Organization, Studies and Reports, New Series, No. 54. Geneva: The Office.
Keyfitz, Nathan 1950 The Growth of Canadian Population. Population Studies 4:47–63.
Kuznets, Simon; and Rubin, Ernest 1954 Immigration and the Foreign Born. National Bureau of Economic Research, Occasional Paper No. 46. New York: The Bureau.
Lasker, B. 1945 Asia on the Move: Population Pressure,Migration, and Resettlement in Eastern Asia Under the Influence of Want and War. New York: Holt.
Milbank Memorial Fund 1958 Selected Studies of Migration Since World War II. New York: The Fund.
National Bureau Of Economic Research 1929–1931 International Migrations. Edited by Walter F. Willcox. 2 vols. New York: The Bureau. → Volume 1. Statistics,compiled on behalf of the International Labour Office, Geneva, with Introduction and notes by Imre Ferenczi. Volume 2:Interpretations, by a group of scholars in different countries.
Taft, D.; and Robbins, R. 1955 International Migrations. New York: Ronald.
Thomas, Brinley 1954 Migration and Economic Growth: A Study of Great Britain and the Atlantic Economy. National Institute of Economic and Social Research, Economic and Social Studies, No. 12. Cambridge Univ. Press.
Thomas, Brinley 1961 International Migration and Economic Development: A Trend Report and Bibliography. Paris: UNESCO.
United Nations, Bureau of Social Affairs 1953 Sex and Age of International Migrants: Statistics for 1918–1947. Population Studies, No. 11. New York: United Nations.
United Nations, Bureau of Social Affairs 1958 Economic Characteristics of International Migrants: Statistics for Selected Countries, 1918–1954. Population Studies, No. 12. New York; United Nations.
United Nations, Department of Economic AND Social AFFAIRS 1951–1952 International Migration in the Far East During Recent Times. Population Bulletin 1:13–30; 2:27–58.
United Nations, Department of Economic AND Social Affairs 1955 Analytical Bibliography of International Migration Statistics, Selected Countries: 1925–1950. Population Studies, No, 24. New York: United Nations.
United Nations, Department of Social Affairs 1953 The Determinants and Consequences of Population Trends: A Summary of the Findings of Studies on the Relationships Between Population Changes and Economic and Social Conditions. Population Studies, No. 17. New York: United Nations.
U.S. Immigration Commission, 1907–1910 1911 Abstracts of Reports of the Immigration Commission: With Conclusions and Recommendations and Views of the Minority. 61st Congress, 3d Session, Senate Document 747, Vol. 1. Washington: Government Printing Office.
[U.S.] National Science Foundation 1958 Immigration of Professional Workers to the United States, 1953–1956. Scientific Manpower Bulletin No. 8.
Walker, Francis A. 1891 Immigration and Degradation. Forum 11:634–644.
Leslie Page Moch
Human mobility has been fundamental to European societies throughout their histories, yet the role it has played has changed with each era. By the eighteenth century, the social organization of migration took recognizable forms that remain useful in observing migration through to the twenty-first century.
Coerced migrations oust people from home against their will (for example, enslaved Africans and persecuted European Protestants) and forbid their return.
Settler migrations move people (like the English settlers in North America) far from home who were unlikely—but not completely unable—to return.
Career migrations move people at the will of their employers, who determine the movement and the possibility of return home (for example, Spanish and Portuguese Jesuit priests in Central America and Brazil).
Chain migrations link people from a common hometown or village with a particular destination. Operating through human contacts, especially people from home who, once settled at the destination, would help newcomers, this may be the most common organization of migration in peacetime history.
Circular migrations are undertaken by people who mean to return home after a period of time (such as their years as a servant or apprentice in town or their months away at seasonal harvest work).
Local migrations keep movers (like the bride from a neighboring village or worker born in the outskirts of the city) close to familiar faces and routines.
Although both men and women moved, migration was distinct for each sex. More men than women left Europe for the Americas until the twentieth century; moreover, men dominated the large teams of migrant harvesters that circulated through regions in the summers. Most migrants were young, single people, and men and women almost always worked at different occupations—this meant that they often chose different destinations, and even in a large city with work for all, young women were often domestic servants while young men were apprentices or laborers. Because women were more likely to travel short distances to marry or to work as servants, women may have actually been more likely to leave home than young men. In addition, noneconomic motives for migration, such as marriage, family difficulties, and a pregnancy to keep secret played a more significant role for women than for men.
LATE MIDDLE AGES AND THE RENAISSANCE
European society in the late Middle Ages and early Renaissance was primarily rural, yet people were not immobile. Indeed, inquiry into rural mobility has substantially changed our view of European rural history. Trade, exchanges of land, and human relations dictated certain kinds of movements. This remained the case for the coming centuries, to varying degrees. Beggars and pedlars brought news to isolated villages; peasants bought and sold property and moved in free-holding areas. In addition, merchants moved across long distances products that eventually reached elites everywhere: leather from central Spain, wool from England, cloth from Flanders, metals from central German areas, furs and timber from Scandinavia, grain from the north-central European plain, olive oil from the Mediterranean littoral. Finally, social life and church marriage regulations meant that men and women often sought mates outside the confines of their village.
The Protestant Reformation, beginning in 1517, opened a period of wars, repressions, and feuds that marked patterns of mobility. The Peasant Revolt of 1524–1525 marked the beginning of religiously based conflicts that developed into civil wars, the French Wars of Religion, the Dutch Revolt, and the Thirty Years' War (1618–1648), all of which emptied out regions, destroying farmlands and families. In addition, religious struggles led Protestant refugees—the Huguenots—to seek shelter in safe havens such as Calvin's Geneva, England, or the Netherlands. Intolerance moved people through the end of the seventeenth century; when Louis XIV terminated tolerance for Protestants by revoking the Edict of Nantes in 1685, for example, some 160,000 Protestants are estimated to have fled France.
With the European—initially Iberian—explorations of the sixteenth century, Spain and Portugal sent thousands of people (almost all men) across the Atlantic and Indian oceans as soldiers, seamen, priests, and traders. As the spice trade with India developed into the extraction of gold and silver in Mexico and Peru, more Europeans went to seek their fortune and many died abroad. These early explorations had two consequences for the mobility of European peoples. First, the seaports thrived; port cities such as Seville and Lisbon grew as they attracted seamen and potential expatriates from surrounding regions. In addition, men and women served as artisans and servants in these unusually prosperous cities; they came from the regions surrounding the seaports as well as from farther afield. Thus, even the earliest European explorations set off movements within Europe.
This is also true of the trade with Africa, which began as a gold trade under Portuguese auspices in the fifteenth century. This trade turned to a trade in enslaved Africans sold initially to work the mines and sugar plantations of the Americas. To date this was the largest single coerced migration in human history. About 8 million enslaved Africans arrived in the Americas before 1820, dwarfing the 2.3 million Europeans who by then had crossed the Atlantic. At least 9.5 million enslaved Africans arrived between the fifteenth and nineteenth centuries. About half of these went to the Caribbean, a third to Brazil, and only about 6 percent to what became the United States. Not until 1840 did more Europeans than Africans cross the Atlantic.
Nonetheless, the empires and explorations of early modern Europe increasingly affected seaports, small towns, and villages as the Iberian empires gave way in importance to those of the Dutch, English, and French. Both London and Amsterdam, for example, grew fivefold between 1550 and 1650, and more than doubled in the seventeenth century. Amsterdam was fed by people fleeing the Spanish Netherlands after 1550, and its imperial trade attracted immigrants from Germany and Norway as well as rural Dutch. A third of the people married in Amsterdam in the seventeenth century and one fourth of the eighteenth-century marriage partners were from outside the Dutch Republic. Many were Norwegian seamen, but German immigrants were most important: over 28,000 German men married in the city in these centuries, and over 19,000 German women. Many newcomers joined the ranks of seamen, but others—like the German women who were domestic servants—joined the labor force of the booming seaport. The same is true of London: it grew despite being the departure point for thousands of sailors, colonials, and indentured servants in the seventeenth century; moreover, it was the most important vocational training center for apprentices from throughout England as well as the workplace for young women servants and seamstresses from the surrounding regions. Thus, the early European empires affected not only world political and economic patterns, but also patterns of migration and settlement within the continent. Often, the number of people who entered the city far outnumbered its actual increase in population for two reasons: first, many subsequently went to sea as sailors, indentured servants, traders, or adventurers, never to return; second, many worked in the city and then left again to return home or to try another destination. Turnover and temporary migration were incalculably important to early modern cities.
Aside from the mobility affected by overseas exploration and settlement, the European continent was enlivened by continuing patterns of chain migration, circular migration, and local migrations that stirred the countryside and fueled cities. Many more people moved within Europe than left its shores. Chain migrations linked towns and villages to regional and national capitals as, for example, a sister joined her domestic servant sibling in town or village construction workers joined their experienced compatriots in a growing capital. Circular migrations not only sent workers—and elites—to cities and home again, but also organized harvest work. Local migrations characterized most marriage markets and land transfers.
THE EIGHTEENTH CENTURY
Two shifts modified the ongoing migration patterns in the eighteenth century. First, around 1750 the population began to grow throughout Europe in a trend that continued until the late twentieth century. In the 1750–1800 period alone, the population increased by 34 percent. Earlier marriage and fewer disastrous epidemics (such as the bubonic plague) meant that more children survived to need work and food; households and villages were fuller than they had been since the fourteenth century. At the same time, the production of goods in domestic settings—called rural industry, domestic industry, or cottage industry—expanded dramatically, increasing to unprecedented volumes as villagers produced products such as yarn, thread, silk, linen, cotton, ship nails, socks, watches, lace, and shoes in their homes. These fundamental demographic and economic developments affected migration so that two distinct patterns of geographic mobility emerged.
On one hand, rural industry enabled villages, small towns, and certain urban centers to thrive—those that coordinated, finished, and exported domestic products. Precisely the small towns that coordinated this production were the kinds of urban areas to grow in this period, and industrial villages also attracted and retained people more than others. Many rural workers were women because the production of lace and fabric depended on women's work. The Austrian cotton firm Schwechat illustrates the size and composition of the labor force: in 1752, 408 workers worked in and around Vienna finishing cloth, 49 distributed raw material, 436 wove cloth (men's work), and 5,655 women were spinners. Rural production had the general effect of supporting people in industrial regions at home.
On the other hand, not all members of the new generations of the eighteenth century were supported by local economies. For more people, leaving home to work became routine. Indeed, by the end of the eighteenth century, seasonal, circular mobility expanded. In western and southern Europe, seven massive migration systems engaged at least 20,000 people each by 1800, most of whom were men. The greatest number of workers in the north traveled to the Paris basin where harvest work in the Ile-de-France and the city created a double attraction; they came from throughout France to work as laborers, traders, and harvest workers. The system that brought men to Holland was next most important, including up to 30,000 men at its peak; they came from Germany and France to work as sailors, servants, and harvesters. A third system in the north brought some 20,000 people to work in London and the home counties; from Ireland, Scotland, and Wales, they divided between urban laborers and harvest workers. The largest system in the south drew about 100,000 workers per year to Corsica, Rome, and Italy's central plain; harvest workers in vineyards and wheatfields and construction workers hailed primarily from Italy's mountainous provinces. The Po Valley engaged about 50,000 people; mountain-dwellers came to its rice fields and construction sites in Turin and Milan. Madrid and Castile attracted not only 60,000 workers from Galicia in northwest Spain, but also an army of upland French; these two groups of workers performed urban work as well as grain harvesting. Finally, the Mediterranean littoral, from northeastern Spain to Provence in eastern France, brought some 35,000 people out of the highlands every year to harvest grain and grapes, and to perform tasks in Barcelona and Marseille. These seven systems were essential to the workings of eighteenth-century European economies, and forecast future systems of circular migration by their size and importance.
THE NINETEENTH CENTURY
During the one hundred years between the fall of Napoleon and the opening shots of World War I (1815–1914), demographic and economic shifts again reshaped patterns of human mobility. The first of these is the astonishing growth of the population of Europe. The population of 187 million in 1800 grew to 468 million by 1913, increasing 42 percent in the first half of the century and another 76 percent by World War I. Behind this population growth lay high birthrates, a decrease in deaths from disease, and improved production and distribution of food. Consequently, European populations expanded more rapidly than those of Africa and Asia. In fact, Europeans and people of European origin were 22 percent of the world's population in 1800, and such people were 38 percent of the global population on the eve of World War I.
The second shift is the collapse of rural livelihoods, which began in Britain, to the west, and moved, unevenly, by region, to the east and south. Small farms and subsistence agriculture increasingly gave way to large-scale cash crops, such as the sugar beet. Crops failed: the potato famine in Ireland in the early 1840s is the most disastrous example of food shortages that were widespread, especially in the "hungry forties." Rural industries failed in region after region under the pressure of competition from mechanized industry; they had allowed hundreds of thousands of country people to survive.
Third, mechanized industry took hold in Britain, then on the continent, expanding not only industrial productivity and trade, but also the service sector of urban society. Relatedly, changes in transportation technology furthered long-distance movement, although much mobility, including urbanization, occurred in short regional moves. In the long run, these changes produced an urban society in Europe. By 1900, over half the British lived in towns of over 20,000, as did one-quarter of Belgians and Dutch and one-fifth of Germans and French. Urbanization, the growth in the proportion of people living in cities, is a central characteristic of this period when village society lost its preeminence as urban growth outstripped rural growth.
The collapse of rural livelihoods and the insecurity engendered by these collapses is at the heart of migration shifts, which left millions of people (particularly young people) with few alternatives to departure. Employment as farm hands (farm servants), which had engaged young men and women in annual contracts, was reduced as farm routines were increasingly dictated by the rhythm of cash crops; this meant that fewer people had year-round employment and more joined the teams of sugar beet workers, grain harvesters, and potato diggers that increasingly traveled to large farms to work for a period of weeks or months. The great systems of circular migration of 1800 described above gave way to larger systems of rural workers. For example, at midcentury 50,000 Irish per year worked in England between the time they planted their potatoes in February and harvested them in November. Over 264,000 male and 98,000 female agricultural workers in France moved in seasonal migration circuits, not counting the foreign harvesters like Belgians who harvested grain in northern France. The number of people working the vine harvest—intense, short-term work—reached nearly 526,000 men and 352,000 women. After 1850, when sugar beet cultivation became more important, 50,000 Belgians cut sugar beets in France and over 100,000 international workers (Russians, Poles, and Scandinavians) worked in Saxony. Poles—many of them women—from Galicia went east to Russia and west into German territories to work sugar beet and potato fields. Germany regulated the movement of its international workers to ensure their temporary status, especially Poles, who were required to return home from December to February. Thus, the agricultural labor force was international and mobile in 1914.
This is also true of the labor force that constructed the new transportation infrastructure of the nineteenth century, the railroad. Begun in England in the 1830s and 1840s, then Belgium, the Low Countries, then France, Germany, and Italy in the rest of the century, this was seasonal, outdoor work blasting out tunnels, building bridges, grading railroad beds, and laying rails. Railroad construction employed people willing to live in makeshift barracks in remote areas; these were often foreign workers: the Irish in England, Poles in Germany, and Italians in Germany, France, and Switzerland.
If temporary work was the hallmark of the countryside, it was also true for cities. Most important, the expanding cities of Europe were built by seasonal labor; housing, commercial spaces, public facilities, and urban infrastructures such as streets, sewer systems, tram lines, and subways were based on the summer work of men in the construction trades. Workers from Spanish Galicia and northern Portugal built Madrid, construction workers from Poland and Italy labored in the Rhine-Ruhr zone, masons from central France built Paris and Lyon. By 1907, over 30,000 Italians were at work in excavation and masonry in Germany, over 57,000 in construction—this in addition to the 14,000 German brickmakers from Lippe, whose migrant labor shadowed the construction season.
After the countryside, cities were the second great destination of the nineteenth-century European migrant. Millions of men and women moved to cities and—due to insecurity, a desire to return home, or a new opportunity—moved on. It is the net number of people who stayed on who ultimately created an urbanizing continent. Some cities mushroomed where there had only been small towns before; this enormous growth was the hallmark of the industrial age. Many newcomers were women, drawn to the textile towns that offered so much employment in spinning mills in the early industrial period. Manchester, for example, the first city of the industrial revolution, was home to over 41,000 people in 1774, nearly 271,000 by 1831, and over 600,000 in 1900. On the other hand, men outnumbered women in the metalworking and coal towns of the Ruhr Valley. Duisburg, at the confluence of the Rhine and Ruhr rivers, grew from 8,900 in 1848 to nearly 107,000 in 1904. Most cities with a longer history were commercial and administrative centers, and added some industry on their peripheries; their newcomers were proletarian laborers, domestic servants, dressmakers, artisans, clerks, and other service workers. Paris, for example, grew from 547,000 to over 2.5 million during the century; more typically, the provincial town of Nimes in southern France grew from 40,000 to 80,000.
The third great destination of nineteenth-century migrants lay beyond the Atlantic Ocean. Transoceanic migration was not new, but greatly expanded on previous trends. For example, about 1.5 million people had emigrated from Britain to North America in the eighteenth century; some 125,000 German settlers in North America had been increased by about 17,000 mercenaries who stayed on after the American Revolution. After 1815, 30,000 to 40,000 European migrants came to the Americas annually. Then in the 1840s, mass migrations began, fueled by two trends. On one hand, the demand for labor exploded in the farmlands and cities in North America and the sugar and coffee plantations of Latin America. Particularly in Latin America, the abolition of slavery was behind this demand for plantation workers. For example, Brazil, which had absorbed 38 percent of enslaved Africans since 1500, outlawed slavery in stages, from the abolition of the African slave trade in 1851 to the Golden Law of full abolition in 1888; consequently, it recruited Europeans (especially Italians) in hopes of replacing its field workers. On the other hand, Europe's "hungry forties," political struggles, and huge population growth exacerbated suffering and employment and thereby encouraged emigration. Transatlantic departures pushed into high gear as 200,000 to 300,000 Europeans departed in the late 1840s. Most dramatically, during the worst years of the potato famine in Ireland (1846–1851), a million Irish perished and another million set out for England and the United States; at this time the Germans and Dutch, also hard-hit, set out for the United States. Even this number increased so that an estimated 13 million embarked between 1840 and 1880 and another 13 million between 1880 and 1900. About 52 million migrants left Europe between 1860 and 1914, of whom roughly 37 million (72 percent) traveled to North America, 11 million (21 percent) to South America, and 3.5 million (6 percent) to Australia and New Zealand. About one-third of the emigrants to North American returned home.
THE TWENTIETH CENTURY
By the eve of World War I, mobile Europeans crossed the countrysides in work teams, entered the growing cities of the continent, and tried their fortunes abroad; at every destination, many men and women returned home or tried another destination. In many cases, they were part of an international labor force in city and countryside—whether in Europe or the Americas—laboring in factories, fields, offices, and middle-class kitchens. On the continent in 1910, there were over one million foreign workers in Germany, among them nearly 600,000 Poles and 150,000 Italians; foreigners were about 2 percent of the population. France, too, harbored over a million foreigners, over 400,000 Italians and nearly 300,000 Belgians; foreigners constituted about 3 percent of the population. Foreign immigrants were even more important in Switzerland, where nearly 15 percent of the population and 17 percent of the labor force were foreigners, with over 200,000 each of Germans and Italians. Most foreign laborers in western Europe were Polish, Italian, Belgian, or German, but the working reality of the immigrant labor force was more complex than that. Consider the frustrated foreman in the Ruhr Valley in 1901 who could not understand any of the thirty workers under his supervision—despite the fact that he spoke five languages! His work crew were Dutch men from the northwestern Netherlands, Poles from eastern German territories, and Croatians.
World War I. These vast flows of migrants changed suddenly with the outbreak of World War I, heralding a century of dramatic shifts in patterns of mobility and increasing state control—at least attempted control—of migration. With the outbreak of hostilities in the summer of 1914, overseas migrations nearly ceased, and in 1915, many Europeans returned home to fight. In Europe, the majority of Germans returned to their country. Not everyone was free to go home, however, and wartime meant labor recruitment and coerced migration. In the interests of the German state, over 300,000 Russian-Polish seasonal industrial and agricultural workers were kept on; where they had been forced to return home annually before the war, they were now forbidden to return. Russian Polish men of military age were retained so that they could not join enemy armies. Germany also used prisoners of war and recruited Belgian workers by force in the winter of 1916–1917, when over 100,000 Dutch and Belgians worked behind German lines. France used similar tactics, expanding its wartime labor force with prisoners of war and contract labor from Greece, Portugal, Spain, Italy, Algeria, Indochina, and China.
The twentieth century was an age of coerced migration for Europeans and for people worldwide. With the end of the war came the first great refugee movement of the century. The war, then revolution and civil war in Russia set off a stream of 500,000 refugees and exiles into Germany, 400,000 into France, and 70,000 into Poland; this stopped only when the border of the USSR closed in 1923. The years of war had forced migration from Polish territories, so that about 700,000 Poles were repatriated by 1923. An estimated 200,000 Germans were repatriated, many from the eastern provinces of the Reich that were returned to a reconstructed Poland after the Versailles settlement. In the west, about 120,000 Germans from Alsace-Lorraine fled into the Rhineland, and 50,000 French moved into Alsace-Lorraine as it once again became part of France. This war, then, not only killed 10 million, but was also the impetus for the flight of Russians, Poles, and Germans to the west and the resettling of people around Alsace and the Rhineland.
After the war, the United States restricted immigration by passing laws in 1921 and 1924 that instituted restrictive national quotas on southern and eastern Europeans, especially cutting off the immigration of Poles and Italians that had been so significant before 1918. Immigration to Germany was reduced as well, since it was plagued by inflation and unemployment in the 1920s; the 2 million foreigners in 1918 were reduced to 174,000 by 1924. (Nonetheless, Germany continued to regulate foreign labor, especially in agriculture, where some 50,000 Polish workers came for the beet and potato harvests in 1920.)
By contrast, the state of France encouraged immigration. It allowed Russian and Polish political émigrés to build communities and also encouraged foreign workers for the rebuilding of war-destroyed areas and repletion of its labor force. The state eased the entry of a million reconstruction workers between 1919 and 1924; commercial recruiters brought many Poles—33,000 for sugar beet and wheat harvests, and 139,000 for the mines of northern France—who formed a cohesive and important minority. In addition, an increasing number of Spanish and Italians entered southern France. On the eve of the Depression, France had an unmatched number of foreign workers, 1.6 million, including, in order of importance, Italians, Poles, Spaniards, Belgians, Germans, Swiss, Algerians, Russians, Yugoslavs, Czechs, and Romanians.
With the Depression of the 1930s and the unemployment it engendered, the flow of workers throughout Europe altered dramatically. Most countries encouraged repatriation and restricted entries of foreigners. Germany closed its doors; by 1932, only 108,000 foreign workers remained, most of whom were longtime residents with permanent visas, and only 5,000 were agricultural workers. Only France was needy enough to require a significant bedrock of foreign workers, because its labor force had been so depleted by World War I and because its birthrate had long been low.
The movement of refugees began again between the wars, as fascist victories ousted political enemies and specific ethnic groups. For the victims of fascism in Italy, Germany, and Spain, France was the most important asylum on the continent. The first to exit were Italians who left in the wake of Mussolini's ascension to power in 1922. With Hitler's appointment as chancellor in Germany in 1933, 65,000 Germans left the Reich, about 80 percent of whom were Jews. Refugees of the 1930s faced restrictions, bureaucratic sluggishness, and anti-Semitism. Between 1933 and 1937, over 17,000 Germans, 80 to 85 percent of whom were Jews, found asylum in the United States. The Jews of Poland, Romania, and Hungary, who far outnumbered German Jews, were also in flight, because their home states increasingly persecuted Jews. As conditions in Central Europe deteriorated, Polish Jews predominated among the nearly 62,000 who found refuge in Palestine in 1935. By the eve of World War II, 110,000 Jewish refugees, many of whom were attempting to leave the continent altogether, were spread throughout Europe—about 40,000 in France, 8,000 in Switzerland, and many among the 50,000 people who found asylum in England in the 1933–1939 period. In 1939, France was literally awash in refugees, as some 450,000 Spanish republicans who came in the wake of Francesco Franco's victory in the Civil War joined those fleeing fascism in Italy, Germany, and Central Europe.
World War II. With the outbreak of war, the uprooting and displacement of peoples began on a monumental scale. On the western front, refugees fled before the German armies; by the end of May 1940, 2 million French, 2 million Belgians, 70,000 Luxembourger, and 50,000 Dutch were displaced and destitute in northern France. One-fifth of the French population fled toward the south. That summer, 100,000 French left Alsace-Lorraine as Germany repossessed this territory.
These upheavals in the West were less severe than those in the East, where masses of people were deliberately uprooted by Nazi policies and Soviet displacements. For example, Germany divided Poland into a western zone that was incorporated into the Reich and an eastern zone (the "General Government") for unskilled slave labor. Quickly, 1.5 million Poles, including 300,000 Jews, were deported to the General Government to make room for the favored German ethnics, like those from the Baltic states, who were uprooted with equal speed. European Jews who were trying to flee were caught in two forces by the end of 1941, when the final solution became defined as the murder of all European Jews: on one hand, avenues of escape dried up as the United States and Palestine both resisted entrants; on the other, Nazis began to round up Jews and send them to the General Government.
Other Europeans were pulled into the German Reich to be part of its wartime labor force. Early on, two million workers from the defeated nations and two million prisoners of war were coerced or persuaded to work in German fields and factories; by 1944, one worker in five was a foreign civilian or prisoner of war and Germany's forced laborers numbered over 7 million, primarily Soviets, Poles, and French.
With the war's end in 1945, millions of people took to the road. Forced laborers and prisoners of war returned home, and by the time the winter of 1945–1946 closed in, most of 11 million people moving west were repatriated. With the German retreat from the east, came two major, permanent shifts of European people and the second great refugee crisis of the century. The first shift was a move from east to west, as the advance of the Soviet army sent Germans fleeing into Germany—even long-established German minorities in central and eastern Europe. This marked the end of the historic eastward movement of Germans. The second shift was the destruction of European Jewry. The Allies anticipated that at least a million Jewish refugees would be found at the end of the war, but the number fell far short of that; for example, of Poland's Jewish community of greater than 3 million people, only some 31,000 (2.4 percent) survived. (Of those remaining, many Jews chose to leave Europe after the war, including some 340,000 who settled in Israel in the 18 months after its founding.) All told, the number of people displaced by the 1939–1945 war in Europe amounted to 30 million—men, women, and children of Eastern, Central and Western Europe who were displaced, deported, or transplanted in wartime.
The dramatic coerced migrations of wartime and large-scale prewar labor migrations occurred against a backdrop of ordinary movements that had long animated the lives of Europeans, such as moves to another village, regional city, or capital. By the end of World War II, however, fundamental changes at work in Europe since about 1880 altered the nature of migration for the second half of the century: levels of education and literacy had increased; European birthrates had declined; and European states were regulating foreigners with greater care. After 1950, the continent increasingly sought foreigners for unskilled jobs in agriculture, production, and services. Such people were in demand especially as smaller generations came to maturity. States sought them out, recruited them, and attempted to control their movements.
The immediate postwar period marked a fundamental shift in migration patterns that endured for the remainder of the twentieth century: there was adequate work in Europe for its people so that relatively few departed; indeed, the days of mass labor migration to the Western hemisphere had definitively ended. Concomitantly, Europe became a continent of immigration, and northwestern Europe a core attraction for Asians and Africans, as well as for Europeans from the south and east. The work of postwar rebuilding occupied the surviving population—and much of the new population. In the case of Germany, newcomers included 12 million Volksdeutsch refugees, who reached western Germany between the end of the war and 1950. From farther away came Asian Indians, members of now-independent nations of the New Commonwealth who numbered 218,000 by 1951; they joined England's immigrants of long standing, the Irish. These immigrants of the late 1940s and 1950s signal two demographically vibrant sources for newcomers to northwestern Europe: former colonies (which increased with decolonizations in the 1960s and 1970s), and the nations of southern Europe and the Mediterranean basin.
The foreign workers of postwar Europe echoed historical patterns and processes. These men and women entered the labor market at times when the deaths and low birthrates required new workers to substitute for a demographic lacuna; the twentieth-century migrants filled places left by the World War II dead and by the low birthrates of the depression just as previous migrants filled places left by the Thirty Years' War and other disasters. The newcomers complemented the place of the native-born in the labor force by taking the difficult, low-status jobs that Europeans avoided. Like the migrants in eighteenth- and nineteenth-century Europe, most postwar immigrants came from regions short on capital and long on population, regions much poorer than northwestern Europe. Moreover, the migration processes were similar to those of the past: most postwar migration streams were pioneered by men, but came to include a significant proportion of women. Like earlier migrants, the men who founded these migration streams to northwestern Europe intended to maintain or enhance their lives at home with money earned abroad; they came for months or years, but they did not intend to remain in Europe. As they had in the past, however, many stayed, sent for their families, and became a permanent part of European society.
Immigration into northwestern Europe increased dramatically between 1950 and 1972 as postwar rebuilding gave way to a prolonged economic boom. Like the 1880–1914 period, the postwar economic success created a time of intense capital formation, which engendered massive international migration. New Commonwealth nations (former British colonies in the Caribbean, the Indian subcontinent, and Africa) and East Germany both sent a flood of immigrants until they were cut off by the Commonwealth Immigrants Acts of 1962 and the construction of the Berlin wall in 1961. Western Germany (the Federal Republic of Germany, FRG) recruited workers through bilateral agreements with Italy and then with Turkey, Morocco, Portugal, Tunisia, and Yugoslavia. By 1971, over 3.2 million residents of the FRG, about 5 percent, were foreign born. These included over a million Turks, nearly 750,000 Yugoslavs, and over 500,000 Italians. At the same time, France housed about 3.3 million immigrants, approximately 6.7 percent of its population. The largest group of new arrivals were Algerians (nearly 850,000) who came to France in the wake of Algerian independence in 1962, in addition to 1.8 million southern Europeans from Italy, Spain, and Portugal. Although their numbers were fewer, foreigners also flocked to Switzerland, where 750,000 immigrants made up 16 percent of the population; the majority (500,000) came from Italy, but also from Spain, Yugoslavia, and Turkey.
All in all, the northwestern European countries of the FRG, France, Switzerland, Belgium, and the Netherlands hosted nearly 8 million nationals from Italy, Spain, Portugal, Greece, Yugoslavia, Turkey, Tunisia, Algeria, and Morocco in the early 1970s. With the exception of Algerians in France and other former colonials, most foreign nationals were thought of as temporary residents by host nations, or "guestworkers" (Gastarbeiter) as they were called in Germany. The majority were men who had come to work, and especially in Switzerland (where foreign workers from the south lived in barracks as they rebuilt the infrastructure of Geneva) had limited rights to stay. There the language problem on work sites could be like it was in 1910 because labor teams combined men of different nationalities; ironically, although the city of Geneva specialized in international communications and hosted a well-educated corps of diplomatic, professional, and clerical employees, the construction workers—from central Spain, from southern Italy, from Bosnia—shared only a few words.
The expectation that foreign residents were temporary migrants was tested—and proven wrong—in the wake of the oil crisis, inflation, and recession that began in 1973. Over half of the eight million foreigners in northwestern Europe were wives, children, and other relatives who were not working (or did not report employment). Like circular, temporary, migrants in past centuries, the workers of the 1960s were willing to distort their lives considerably—to work at difficult, demeaning, and dangerous jobs; to tolerate very bad housing—as long as these conditions were temporary. However, migrant workers had not been willing to forego all hope of a family life. They had arranged periodic returns home, married at destination, or had sent for their wives. Some wives had been recruited as laborers in their own right, and many children were brought along or born in the host country. In any case, migrant communities had changed, and their demographic structure by 1973 more resembled immigrant communities than temporary labor groups.
Nonetheless, host countries made vigorous efforts to stop immigration altogether. In November of 1973, the FRG banned entries of workers from non–European Community nations and within a year several other governments did the same. France banned the entry of dependents as well as of workers, then offered a repatriation allowance. The Netherlands and Germany began assistance plans for Yugoslavia and Turkey to increase employment in workers' home countries. No country except Switzerland, however, instituted the stringent measures necessary to keep foreigners out, efficaciously barring the entry of dependents. The attempt to shut off immigration was fundamentally unsuccessful, and more dependents joined their relatives in northwestern Europe. The absolute number of foreign residents increased by 13 percent in the FRG between 1974 and 1982, by 33 percent in France (1969–1981) and by 13 percent in Britain (1971–1981). Although the flow of newcomers was reduced from the 1960s, the total numbers of foreign residents did not diminish and they appeared to be "guests come to stay."
The economic crises of the early 1970s sharpened hostility to foreign workers and gave birth to several anti-immigrant political movements that retained their energies through the end of the century. European prejudices—irritated by the phenotypical distinctiveness of many foreigners, their visibility in local labor markets, and their numbers in many cities—fed off social stress and fueled antiforeign incidents. Algerians were murdered in southern France and their wives were denied residence permits in the north. Similar actions against Pakistanis in Britain and against Turks in Germany reflected growing hostility to immigrants, particularly to those who were distinct in race or ethnicity. Resentment was fueled as foreigners became more visible as their children entered school systems, social welfare programs attended to their families, and public housing attempted to eradicate the shantytowns that had spread on the edge of many a metropolis. Organized racist groups such as the National Front in Britain, and neo-Nazis in the FRG, and anti-immigrant political parties such as the Front National in France, and the Centrum Partij in the Netherlands, expanded in the anti-immigration politics of the 1970s. The large proportion of Muslims among newcomers in Europe called forth a particularly strong response, as an anti-Muslim bias was deep-rooted and of long standing in Europe. Like many migrants throughout history, Muslims who entered European urban society brought distinct patterns of gender relations, fertility, and labor force participation.
Migration to Europe of significant, but stable, ethnic minorities and immigration patterns shifted again shortly before the European Union was to be finalized in 1992. The opening of the Berlin Wall in 1989, followed by the unification of Germany in 1990 and the collapse of the Soviet Union in 1991, put Germany at the center of a host of migration streams, including East-West movement of labor migrants, asylum-seekers, and ethnic Germans from the former Soviet Union, Poland, Romania, and other Eastern European countries. Under German law, ethnic Germans have rights to citizenship; 397,000 of these Aussiedler arrived in 1990, 148,000 from the Soviet Union, 134,000 from Poland, and 111,150 from Romania. Fears proved groundless that an open Europe, shut off from the East by Cold War policies, would become a "Fortress Europe" implementing exclusionary policies to keep out East Europeans; although Germany received great numbers of ethnic Germans and refugees, by the end of the twentieth century there was no great flood of Eastern Europeans to the west. Rather, Poland and Hungary were becoming nations of immigration. Refugees from the Balkan wars of the 1990s were part of a formidable contingent of asylum-seekers from countries such as Eritrea, Afghanistan, Chile, Argentina, and Vietnam, as well as from eastern and southern Europe.
The close of the twentieth century, then, found Europe transformed by the human mobility of the century, which showed no signs of slowing in a global age of migration. The foreign-born, and their children, were an important contingent in the increasingly diverse societies of this continent. In 1990, there were 1.9 million foreign citizens in the United Kingdom (3.3 percent of the total population). European Community nationals made up nearly half the foreign-born, signaling the fruits of free movement among members of the European Union; the largest single groups in Britain were the 638,000 Irish, followed by 155,000 Asian Indians. Foreign residents made up 6.4 percent of France's total population, where the most significant groups were 646,000 Portuguese, 620,000 Algerians, and 585,000 Moroccans. The 4.6 percent of the Dutch population that was foreign came largely from Turkey (204,000) and Morocco (157,000). In Switzerland, where 16.3 percent of the population was foreign born in 1990, the largest groups were the 379,000 Italians, 141,000 Yugoslavs, and 116,000 Spaniards. It is difficult to discern the foreign-born in Germany, where newcomer Germans are counted as citizens, but in 1990, Turks remained the largest immigrant group at 1.6 million people, followed by Yugoslavs.
The reception of newcomers continued to be ambivalent at the opening of the twenty-first century. Although Europe needed laborers, the parties set against immigration, such as France's Front National and Austria's Freedom Party, were political forces to be reckoned with, German conservatives urged people to have more children rather than to accept immigrants, and Britain marshaled laws against the tide of asylum seekers. On the other hand, some children of immigrants enrolled in universities and others held skilled positions. Human mobility and intrepid migrants were, as ever, at the heart of European society.
Berger, John, and Jean Mohr. A Seventh Man: Migrant Workers in Europe. New York, 1975.
Bretell, Caroline. Men Who Migrate, Women Who Wait: Population and History in a Portuguese Parish. Princeton, N.J., 1986.
Brubaker, Rogers. Citizenship and Nationhood in France and Germany. Cambridge, Mass., 1992.
Canny, Nicolas, ed. Europeans on the Move: Studies on European Migration, 1500–1800. Oxford, 1994.
Castles, Stephen, and Mark J. Miller. The Age of Migration: International Population Movements in the Modern World. New York, 1993.
Castles, Stephen, Heather Booth, and Tina Wallace. Here for Good: Western Europe's New Ethnic Minorities. London, 1984.
Clark, Peter. "Migration in England during the Late Seventeenth and Early Eighteenth Centuries." Past and Present 83 (1979): 57–90.
Cross, Gary. Immigrant Workers in Industrial France: The Making of a New Laboring Class. Philadelphia, 1983.
De Vries, Jan. European Urbanization, 1500–1800. Cambridge, Mass., 1984.
Hochstadt, Steve. Mobility and Modernity: Migration in Germany, 1820–1989. Ann Arbor, Mich., 1999.
Hohenberg, Paul, and Lynn Lees. The Making of Urban Europe, 1000–1994. Cambridge, Mass., 1995.
Hollifield, James. Immigrants, Markets, and States: The Political Economy of Postwar Europe. Cambridge, Mass., 1992.
Hoerder, Dirk, and Leslie Page Moch, eds. European Migrants: Global and Local Perspectives. Boston, Mass., 1996.
Jackson, James H., Jr. Migration and Urbanization in the Ruhr Valley, 1821–1914. Altantic Highlands, N.J., 1997.
Kofman, Eleonore. "Female 'Birds of Passage' A Decade Later: Gender and Immigration in the European Union." International Migration Review 33, no. 126 (1999): 269–299.
Koser, Khalid, and Helma Lutz, eds. The New Migration in Europe: Social Constructions and Social Realities. New York, 1998.
Kulischer, Eugene. Europe on the Move: War and Population Changes, 1917–1947. New York, 1948.
Kussmaul, Ann. Servants in Husbandry in Early Modern England. Cambridge, U.K., 1981.
Lees, Lynn. Exiles of Erin: Irish Migrants in Victorian London. Ithaca, N.Y., 1979.
Lucassen, Jan. Migrant Labour in Europe, 1600–1900: The Drift to the North Sea. Translated by Donald A. Bloch. London, 1987.
Lucassen, Jan, and Leo Lucassen, eds. Migration, Migration History, History: Old Paradigms and New Perspectives. Bern, Switzerland, 1997.
Marrus, Michael. The Unwanted: European Refugees in the Twentieth Century. New York, 1985.
Moch, Leslie Page. Moving Europeans: Migration in Western Europe since 1650. Bloomington, Ind., 1992.
Noiriel, Gérard. The French Melting Pot: Immigration, Citizenship, and National Identity. Translated by Geoffroy de Laforcade. Minneapolis, Minn., 1996.
Ogden, Philip, and Paul White, eds. Migrants in Modern France: Population Mobility in the Later Nineteenth and Twentieth Centuries. London, 1989.
Pooley, Colin, and Jean Turnbull. Migration and Mobility in Britain since the Eighteenth Century. London, 1998.
Tilly, Charles. "Migration in Modern European History." In Human Migration: Patterns and Policies. Edited by William McNeill and Ruth Adams. Bloomington, Ind., 1978. Pages 48–74.
Weber, Adna. The Growth of Cities in the Nineteenth Century. 1899. Reprint, Ithaca, N.Y., 1963.
Yans-McLaughlin, Virginia. Immigration Reconsidered: History, Sociology, and Politics. New York, 1990.
Migration is a demographic process that has played an increasingly important role in the changing populations of many countries around the world. Much of the geographic shift in populations occurs from rural areas to urban areas, as well as from less developed countries to more developed countries. Since the mid-twentieth century, an expanding literature has been developed to understand migration. In particular, many scholars have focused not only on the forces encouraging people to migrate, but also on the impact that this migration has had on the migrants themselves and on their places of origin and destination. This interest in the topic of migration emerges not only from the increasing prevalence of people migrating, but also the relevance of migration in shaping demographic, social, economic, and political spheres worldwide.
Migration has been defined generally as a “permanent or semi permanent change of residence” (Lee 1966, p. 49). This definition places no restriction “upon the distance of the move or upon the voluntary or involuntary nature of the act, and no distinction is made between external and internal migration” (Lee 1966, p. 49). However, such a broad definition obscures the heterogeneous types of movements that exist based on geographical distance, as well as the factors involved in the different types of movements. For example, some people move within a community, others move across counties within the same state, others move across states, and others move across international boundaries. The U.S. Census Bureau collects information on the migration activities of people using the five-year migration question (location of present residence and location of residence five years earlier). Furthermore, the U.S. Census Bureau defines movers as those who lived in a different house but within the same county in the five-year period, migrants as those that moved at least across counties within the country during the period, and international migrants as those that were living outside of the United States five years earlier. The five-year migration question has numerous shortcomings, most notably that it is based on only two points in time. For instance, persons living in the same county in 1995 and 2000 but who lived in another county in the interim are classified as nonmigrants.
The process of accounting for the continuous movement of people has become complicated by technological advances in the areas of transportation and communications. For example, immigrants increasingly engage in transnational migration, which involves the continuous movement between the community of origin in the home country and the community of destination in the host country (Levitt 1998). This type of movement has important implications beyond the migrant’s experience because it produces a variety of changes for both the sending and the receiving community.
The theorizing of explanations for the movement of people extends back to the late nineteenth century with geographer E. G. Ravenstein’s (1834–1913) article “The Laws of Migration” (1885). Interest in the development of theoretical perspectives to explain migration resurfaced between the 1950s and 1970s with important works by William Petersen (1958), Everett Lee (1966), and P. N. Ritchey (1976). However, the changing nature of migration—especially the increasing prevalence of international migration—has seen the development of theoretical perspectives that place greater attention on immigration since the 1960s (see Massey et al. 1993). This entry describes some of the most prominent perspectives.
World-Systems Perspective The world-system perspective is a structural-macrolevel perspective developed by sociologist Immanuel Wallerstein. This perspective views international migration as the result of the expansion of the market economy throughout the world, as capitalists from core countries make inroads into peripheral and semiperipheral countries (Brettell 2000; Massey and Espinosa 1997; Portes 1998; Sassen 2001; Wallerstein 1974). Accordingly, the flow of capital into peripheral and semi-peripheral countries, such as Mexico, results in a counter-movement of labor from such countries to core countries, such as the United States (Massey and Espinosa 1997). This perspective highlights the links between the movement of capital and the countermovement of labor. To a large extent, emigrants from periphery countries migrate to “global cities” (Sassen 2001), which are urban centers in which “banking, finance, administration, professional services, and high-tech production tend to be concentrated” (Massey et al. 1993, p. 447). However, by focusing exclusively on the macrolevel, the world-systems perspective ignores the microlevel factors that encourage people to migrate, while also neglecting the role of politics and the state in social and economic change (Brettell 2000).
Dual Labor-Market Perspective The dual labor-market perspective emphasizes the demands of advanced industrial countries for low-skilled and low-wage labor (Massey et al. 1993). This perspective suggests that immigrants fill jobs that natives shun due to low wages, lack of mobility ladders, lack of benefits, and the arduous and dangerous nature of such jobs. The dual labor-market perspective asserts that the movement of immigrants from less developed to more developed countries is driven by the constant demand for cheap labor in developed countries.
Neoclassical Economics Perspective The neoclassical economics perspective is characterized by attention to both the macrolevel and the microlevel. At the macrolevel, this perspective suggests that migration occurs as a response to a disequilibrium between labor supply and labor demand. Thus, some labor markets have a surplus of labor, which results in high levels of unemployment and low wages. Other labor markets have greater labor demands than the existing labor pool can supply, which results in low levels of unemployment and high wages. This perspective suggests that workers gravitate from labor markets with a greater surplus of labor toward those with a greater demand for labor.
In contrast, the microlevel form of the neoclassical economics perspective focuses on the cost-benefit calculations that individuals undertake when making decisions regarding migration. This perspective treats individuals as utility maximizers who attempt to obtain the highest wages in relation to investments. In considering migration, people weigh the costs of relocation against the benefits that they are likely to receive from moving. People are expected to migrate when the benefits outweigh the costs, whereas they are presumed to remain stable when costs outweigh benefits.
The New Economics-of-Migration Perspective The new economics-of-migration perspective shifts the context to the household and focuses on how such units organize themselves to maximize economic returns while minimizing risks (see Massey et al. 1993). In settings without readily accessible unemployment benefits, bank loans, and insurance to protect against potential failure (e.g., loss of crops due to weather), households are especially vulnerable to a variety of economic and physical calamities. The new economics-of-migration perspective suggests that household members are deployed to undertake a wide variety of employment activities to ensure that the household generates economic resources while minimizing risks. Thus, some household members may remain at home to conduct subsistence agricultural activities, while other household members work locally in the private sector, others migrate to urban areas within the country, and still others move abroad and send remittances to the household. Essentially, the new economics-of-migration perspective proposes that households diversify their investment portfolios to protect themselves against risks and uncertainties.
Social-Network Perspective The social-network perspective emphasizes the interpersonal ties linking potential migrants and former migrants, as well as the migrants’ communities of origin and destination. In particular, the social-network perspective focuses on social relations that exist among family or community members, with special attention to social capital. Alejandro Portes notes that social capital is made up of “those expectations for action within a collectivity that affect economic goals and goalseeking behavior of its members, even if these expectations are not oriented to the economic sphere” (1993, p. 1322). This perspective places primary importance on the social networks that potential migrants have with people who have previously migrated as the most important factor influencing people’s decision to migrate (Massey and Espinosa 1997). Hence, social networks affect the decision of individuals to migrate based on interpersonal ties. Migration is facilitated by sharing information about destination communities, reducing the expected costs and risks of migration, and increasing the expected benefits of migration (Rivero Fuentes 2003). In contrast to the neoclassical economics perspective, the social-network perspective recognizes the nonrational elements involved in people’s migration decision. However, sociologists have also been careful to recognize the shortcomings of this perspective. For example, social capital may prevent the creation of new networks by excluding outsiders, restricting individual freedom, and promoting downward leveling norms (Portes 1998).
Cumulative Migration (or the Migration Syndrome) Perspective Closely connected to the social-network perspective is the cumulative migration (or migration syndrome) perspective. According to this perspective, originating from the social-movements framework, every act of immigration has the potential to facilitate the migration of other people by decreasing the cost of immigration (Massey et al. 1993). Carried to its fullest, migration becomes cumulative and natural when it becomes embedded in the culture of sending communities. In such instances, it is completely expected that certain segments of the population (e.g., the young in many parts of Mexico, especially males) will emigrate. In the case of Mexico, for example, many communities have relatively few working-age men because they have followed the trek of friends and relatives to the United States.
While migration represents an important life-changing event for migrants, it also poses important demographic, social, economic, and political implications for sending and receiving communities. In demographic terms, international migration is responsible for changing the racial and ethnic composition of the communities of destination. For example, the American Latino and Asian populations have expanded tremendously through immigration into the United States since the 1960s (Alba 1999). In addition, with respect to the social implications of immigration, much discussion has focused on issues such as language and racial and ethnic boundaries as examined through the assimilation and multiculturalism models (Alba 1999).
Furthermore, migration has tremendous economic implications for communities, states, and countries around the globe. For example, Peggy Levitt and Rafael de la Dehesa (2003) have pointed out that much public policy on immigration is due to the recognition of migrants and their remittances as crucial elements in the state’s economy. Because of this, many states are reinventing themselves by expanding the boundaries of citizenship and nationality, granting migrants the right to vote, establishing bureaucratic reforms, and making investments that allow states to become more efficient in aiding migrants within and across their own borders.
As noted earlier, and as predicted by contemporary theoretical perspectives on migration, people generally move from less developed to more developed countries. The future points increasingly to this scenario. Of the 2.8 billion people that are projected to be added to the world’s population between 2005 and 2050, nearly all (98.6%) are expected to be added to the populations of developing countries (Population Reference Bureau 2005). Developed countries, with increasingly aging populations and low fertility rates, are projected to account for only 1.4 percent of the world’s population growth between 2005 and 2050. Given continued economic disparities across the developed and developing worlds, increasing global population shifts are likely.
SEE ALSO Immigrants to North America; Migrant Labor
Alba, Richard. 1999. Immigration and the American Realities of Assimilation and Multiculturalism. Sociological Forum 14 (1): 3–25.
Brettell, Caroline B., and James F. Hollifield. 2000. Migration Theory: Talking across Disciplines. In Migration Theory: Talking across Disciplines, eds. Caroline B. Brettell and James F. Hollifield, 1–26. New York: Routledge.
Brown, David L. 2002. Migration and Community: Social Networks in a Multilevel World. Rural Sociology 67 (1): 1–23.
Conway, Karen Smith, and Andrew J. Houtenville. 1998. Do the Elderly “Vote with Their Feet?” Public Choice 97: 663–685.
De Jong, Gordon F., Rex H. Warland, and Brenda Davis Root. 1998. Family Interaction and Migration Decision Making. Research in Rural Sociology and Development 7: 155–167.
Lee, Everett S. 1966. A Theory of Migration. Demography 3: 47–57.
Levitt, Peggy. 1998. Social Remittances: Migration Driven Local-Level Forms of Cultural Diffusion. International Migration Review 32 (4): 926–948.
Levitt, Peggy, and Rafael de la Dehesa. 2003. Transnational Migration and the Redefinition of the State: Variations and Explanations. Ethnic and Racial Studies 26 (4): 587–611.
Massey, Douglas S., and Kristin Espinosa. 1997. What’s Driving Mexico-U.S. Migration? A Theoretical, Empirical, and Policy Analysis. American Journal of Sociology 4 (102): 939–999.
Massey, Douglas S., et al. 1993. Theories of International Migration: A Review and Appraisal. Population and Development Review 19 (3): 431–466.
Petersen, William. 1958. A General Typology of Migration. American Sociological Review 23 (3): 256–266.
Plane, David A., and Peter A. Rogerson. 1994. The Geographical Analysis of Population with Applications to Planning and Business. New York: Wiley.
Population Reference Bureau. 2005. 2005 World Population Data Sheet. Washington, DC: Author. http://www.prb.org/pdf05/05WorldDataSheet_Eng.pdf.
Portes, Alejandro. 1998. Social Capital: Its Origins and Applications in Modern Sociology. Annual Review of Sociology 24: 1–24.
Portes, Alejandro, and Julia Sensenbrenner. 1993. Embeddedness and Immigration: Notes on the Social Determinants of Economic Action. American Journal of Sociology 98(6): 1320–1350.
Portes, Alejandro, and Min Zhou. 1993. The New Second Generation: Segmented Assimilation and Its Variants. Annals of the American Academy of Political and Social Sciences 530: 74–96.
Ravenstein, E. G. 1885. The Laws of Migration. Journal of the Statistical Society 48 (2): 167–235. Ritchey, P. N. 1976. Explanations of Migration. Annual Review of Sociology 2: 363–404.
Rivero Fuentes, Estela. 2003. Engendering Migrant Networks: The Case of Mexican Migration. Demography 40 (2): 289–307.
Sassen, Saskia. 2001. The Global City: New York, London, Tokyo. 2nd ed. Princeton, NJ: Princeton University Press.
Wallerstein, Immanuel. 1974. The Modern World-System. Capitalist Agriculture and the Origins of the European World Economy in the Sixteenth Century. New York: Academic Press.
Maria Isabel Ayala
Americans are known as a restless people who travel and relocate, and this restlessness is part of the idea of "American exceptionalism." Euro-America was settled by immigrants who had left their homes for a better life. Many American Indian groups, especially the Plains Indians, were migratory. Some tribes were removed by the U.S. government.
African American slaves, taken by force from Africa, were frequently transferred among owners. When slaves escaped they fled north, often into Canada. After the Civil War tens of thousands of the newly freed slaves migrated to the cities of the North. Thus Americans are a people prone to "movin' on."
THE OKLAHOMA LAND RUSH
A series of events led to the rush by non-Indians for Oklahoma land, part of Indian Territory, created by the Indian Trade and Intercourse Act of 1834. In the late nineteenth century, railroad lines were rapidly covering the United States. The national rail network grew from thirty-five thousand miles in 1865 to ninety-three thousand miles in 1880. During the 1880s more than 70,000 miles of line were built, with 164,000 miles in operation by 1890. In the spring of 1887 the Santa Fe Railroad was completed from Arkansas City, Kansas, to Gainesville, Texas, creating a new passage through Oklahoma. Railroad workers and passengers sometimes settled in the area, creating tent towns, largely ignored by the authorities.
This changed with the violence of the boomers, a group of whites seeking to open the unassigned lands. Named "boomers" because they wanted a boom in real estate development, they brought national attention to the Oklahoma district. Elias Boudinot II (1854–1896), a Cherokee, declared in a Chicago Times article (17 February 1879) that two million acres, unassigned to any tribe, were available for settlement. The Oklahoma Territory, bordered by Kansas on the north, was known for its open, relatively uninhabited prairies of fertile soil. Boudinot's announcement added to a growing state of excitement about free land.
During the 1880s and 1890s Oklahoma's Native Americans were experiencing their own significant changes. The nations were divided concerning non-Indian settlement. At a boomer conference in Kansas City on 8 February 1888, John Earlie of the Ottawa Nation in northeastern Oklahoma supported settlement by non-Indians, believing it mutually beneficial to whites and Indians. Some other nations strongly disagreed with the boomers, protesting "invasion" by "alien forces." Finally several of the Indian nations agreed, some out of desperate financial need, to sell portions of their land to the U.S. government. In early 1889 a proclamation by President Benjamin Harrison opened the Oklahoma areas for settlement by non-Indians. Over the next few years homesteaders were able to settle the land by means of a series of "land runs," actual races by horseback or horse-drawn wagons.
Oklahoma Territory fascinated many adventurous souls, including Huckleberry Finn. At the time of the publication of Mark Twain's Adventures of Huckleberry Finn (1885), the Indian Territory was topical and controversial. Contemporary readers would have understood the significance of Huck's words at the end of the novel: "I reckon I got to light out for the Territory ahead of the rest" (p. 229). However, this statement is an anachronism. The action of the novel is set, according to the author, "forty or fifty years ago," with Huck lighting out long before the territory was open to white settlers.
MIGRATION OF BLACKS
Rutherford B. Hayes, who became U.S. president through the Compromise of 1877, withdrew federal troops from the South, officially ending Reconstruction. Without the support of the national government, many African Americans, former slaves, found themselves in a New South that was as physically and economically dangerous and uncertain as the Old South. They remained susceptible to the racism and hatred of whites, sometimes their former owners, who had recently been defeated in a humiliating war. In the 1880s racial bigotry was legally sanctioned by the passage of Jim Crow laws (named after a character in a minstrel song), legalizing racial discrimination and effectively segregating blacks from whites in the South.
Because African Americans were no longer valuable property, white southerners had very little to lose by terrorizing the former slaves. Blacks were tortured and publicly lynched by white supremacist groups such as the Ku Klux Klan. Leaving the South became a dream and a goal for many blacks. Consequently southern blacks escaped this oppression by moving north, especially to the large metropolitan areas of Chicago, Detroit, Philadelphia, and New York, among others. Some traveled by railroad, some by wagon, and some even walked the hundreds of miles to their new homes.
One organized effort encouraging southern blacks to migrate north was the exodus movement, the participants being called "exodusters." Benjamin "Pap" Singleton (1809–1892) of Memphis, Tennessee, was instrumental in black migration. In 1869 Singleton and Columbus M. Johnson traveled to Kansas to investigate homestead land. While in Tennessee, Singleton and W. A. Sizemore created the Edgefield Real Estate and Homestead Association for fund-raising, transportation, and Kansas homesteading. Singleton and Sizemore also collaborated to achieve the incorporation of the Singleton Colony in Dunlap, Kansas, in June 1879. Later that year migrants from Tennessee and other southern states began arriving in Singleton, Kansas. Singleton organized the Colored Links political party in an African American section of Topeka, Kansas, called "Tennessee Town" because most of its residents were from that state. For a short while he even advocated a large migration to Liberia.
A descendant of an exoduster, Oscar Micheaux (1884–1951) was a noted filmmaker who also wrote semiautobiographical novels about black settlers in the Midwest. In The Conquest (1913), the protagonist works at a series of jobs in northern cities until he purchases a relinquishment on the Rosebud reservation in South Dakota and attempts to homestead his thousand-acre allotment. He fails as a farmer, suffers an unhappy marriage, and is a broken man. Micheaux's The Homesteader (1917) is a chronicle of a black pioneer, Jean Baptiste, who also farms land in South Dakota. Unlike the protagonist of The Conquest, Baptiste succeeds at farming and settles into a happy marriage. In his novels and films Micheaux praises and promotes the ideals of rugged individualism, the work ethic, and moral courage in the face of adversity.
Other African American writers explored the theme of travel and migration. Paul Laurence Dunbar (1872–1906), dubbed "the Poet Laureate of the Negro Race" by Booker T. Washington, established himself as a poet writing in two distinct poetic voices, formal English and southern black dialect. The voices, varying in tone from light humor to somber elegy, are randomly combined in his volumes of poetry. In his novel The Sport of the Gods (titled The Jest of Fate when published in England in 1903), Dunbar relates the migration of the Hamilton family, former slaves, from the South to New York City. Dunbar offers an ambivalent message: the South is economically and socially disastrous for blacks, but the northern urban centers destroy their very souls.
Military enlistment was another important reason for migration and relocation of African Americans. The characters of F. Grant Gilmore's The Problem: A Military Novel (1915) leave their homes in Virginia to serve in Cuba during the Spanish-American War and to settle finally in Washington, D.C. This migration narrative is a treatise on the mixing of races, the "problem" of the title. It is also a polemic extolling the courage and patriotism of "Negro" troops.
In 1896, the year of the "separate but equal" Supreme Court ruling in Plessy v. Ferguson, another African-American novelist, J. McHenry Jones, published Hearts of Gold, a novel of black migration. However, McHenry's novel depicts black migration from the North to the South, and his northern black characters are from the middle and upper classes.
In James Weldon Johnson's (1871–1938) novel The Autobiography of an Ex-Colored Man (1912), the protagonist moves from the South to the North and to Europe. The protagonist lives in the South, Connecticut, New York City, Paris, and London. He finally settles into family life in New York City, feeling guilty because he has chosen to pass as white and not claim his black heritage. The protagonist of Charles Waddell Chesnutt's (1858–1932) "The Wife of His Youth" (1898) is a prominent businessman in his northern town. He is proud of his light skin and his comfortable lifestyle. On the eve of his marriage to a pale, elegant northern woman, he is confronted by an old, uneducated, and very dark woman from the South. She is his first wife, representative of his youth, for whom, out of loyalty and honor, he jeopardizes his place in society.
Usually the first to migrate to the North were the younger men. After finding employment and settling into their new environments, these men would send money home to their families. Eventually, in the usual pattern of migration, they would move their families north. In the large city, young women, particularly if alone, faced their own difficulties. These women were vulnerable to involvement in criminal behavior, particularly prostitution. Organizations were formed to assist these young black women in adjusting to life in urban areas. Foremost among these was the National League for the Protection of Colored Women, established in New York City in 1905. Other organizations were created to unite and empower the new black citizens. The National Negro Business League was formed in 1900, the National Association for the Advancement of Colored People (NAACP) in 1909, and the National Urban League in 1911.
In addition to migration within the United States, some former slaves proposed immigration to Africa, in particular Liberia, as a solution to their problems. Liberia, "founded" by the American Colonization Society in 1817, was extolled by both blacks and whites as a panacea to race and slavery issues. Henry Adams, a freedman from Louisiana who had gained political attention through his work with the Republican Party, campaigned strongly for immigration to Liberia. During the late 1870s and early 1880s, Adams and others with similar feelings gave voice to the anguish and growing frustration of the former slaves by focusing attention on the idea of emigration. Liberia is a setting in Henry F. Downing's The American Cavalryman: A Liberian Romance (1917), a narrative of emotional and political relationships among white Americans, white Liberians, native black Liberians, and Americans of mixed blood.
Marcus Garvey (1887–1940) and the "Garveyites" were among proponents of sending African Americans "back" to Africa. Garvey founded the Universal Negro Improvement Association (UNIA) in Jamaica in 1914. When he migrated to New York in 1916, he moved the UNIA headquarters with him. Garvey's weekly newspaper Negro World, published from 1918 to 1933, was managed and staffed entirely by blacks. The UNIA proposed sending American blacks to Africa not as migrants but as missionaries and ambassadors, bringing education, independence, and Christianity to Africans.
Not all African Americans supported migration. Frederick Douglass (1818–1895) strongly opposed emigration from America to Africa. He argued that American Negroes were, first and foremost, Americans. For these Americans to leave their country would diminish the blacks and the country: "Drive out the negro and you drive out Christ, the Bible, and American liberty with him. The thought of setting apart a State or Territory and confining the negro within its borders is a delusion" (p. 390).
In contrast to the migration to northern cities, some southern blacks sought rural areas in the West and Midwest, where they hoped to purchase or homestead their own farmland. Due to John Brown's highly publicized abolitionist activities in Kansas during the summer of 1856, some African Americans thought of Kansas as a land of freedom. Several black Kansas towns were founded in the late 1870s and early 1880s. Of these, Nicodemus remains the most famous. Located in northwestern Kansas, Nicodemus was founded by African American settlers from Kentucky. Two white real estate developers, W. R. Hill and W. J. Niles, had recruited the settlers for the town. The Nicodemus Historical Society still promotes Nicodemus as "an all African-American pioneer town."
A Nicodemus resident and Kansas state auditor from 1883 to 1887, E. P. McCabe envisioned the settlement of Oklahoma as a black state. He helped found Langston, Oklahoma, forty miles northwest of Oklahoma City on the direct route of the Santa Fe Railroad. A college established in Langston was first named the Colored Agricultural and Normal College, then Langston College, and now Langston University; it remains a predominantly African American university. Liberty, Oklahoma, another black township, was promoted by McCabe and the African Methodist Episcopal (AME) Church but was abandoned because of the racial violence of the white residents of nearby Perry. Boley, Oklahoma, was settled on land previously owned by Creek Nation freedmen. Taft, Oklahoma, was a settlement of black freemen on land bought from D. H. Twine, a prominent black man in the area. The black Blind and Orphan Home, the State Training Institute for black girls, and the state hospital for the insane were established in Taft.
All black migrants did not travel to the North or to the Midwest. In 1900 Frank Boyer and Daniel Keyes walked from Georgia to southeastern New Mexico. On 5 September 1903 Boyer and Keyes, among others, signed the articles of incorporation for the Blackdom Townsite Company in order to establish a "Negro colony." Blackdom was a moderately successful farming settlement even though drilling artesian wells in semiarid New Mexico was very costly. By the early 1920s, due to crop failure and lack of water, residents had abandoned Blackdom. Most relocated in nearby Roswell, Artesia, and Hobbs. These black settlements are among the dozens established between the Civil War and the Great Depression.
Due to economic difficulties, many residents left the black townships, frequently settling in established African American communities in large northern cities. In 1870 U.S. census figures indicate that over thirty-one southern-born blacks had moved from Kentucky or Tennessee to East North Central states, mostly Ohio, Indiana, and Illinois. During the same period, 13,889 Virginia-born blacks were living in Ohio.
Although some African Americans migrated to the North, most moved primarily within the South. As William Cohen states, "The pattern began to change in the 1890s, but it was not until the decade of World War I that the northward movement assumed truly significant proportions" (p. 93). According to Carter G. Woodson, among the first African American historians, the black populations of some major cities increased by several thousand in the decade between 1900 and 1910. Chicago's black population grew from thirty thousand to forty thousand, Philadelphia's from sixty thousand to eighty-five thousand, and New York's from sixty thousand to ninety thousand.
RURAL TO URBAN MIGRATION
In addition to the movement from the South to the North, Americans were moving in large numbers from rural to urban areas. In the decades after the Civil War urban population figures steadily rose, except for the 1870s. The panic of 1873 caused a decrease in manufacturing, and many industrial workers moved to rural areas. From the 1880s through the first quarter of the twentieth century, urban population steadily grew.
The literature of the period reflects this shift from rural to urban population. In the opening passage of Sister Carrie (1900), Theodore Dreiser (1871–1945) writes of the evil city where innocents from small towns and farms are corrupted. In the final section of Sherwood Anderson's Winesburg, Ohio (1919), the young protagonist, as naive as any of the era's innocents, leaves his small hometown for the big city and a career as a journalist. The protagonists of Bayard Taylor's novels John Godfrey's Fortunes (1864) and Joseph and His Friend (1871) leave rural Pennsylvania for New York City.
In Main-Travelled Roads (1891), Hamlin Garland (1860–1940) deals with aspects of the American migration from rural to urban communities. "Up the Coulee" is the story of a man who has moved to the city where he has become accustomed to his life as an actor in the large urban atmosphere. When he returns to his rural home, he realizes that he has very little in common with his relatives and old friends. He has moved beyond his hometown, socially and emotionally. In "God's Ravens" a Chicago man returns to the farmlands of his childhood where he recovers his failing health through the simple kindness and devotion of the farmers. He was unhappy in the city but finds peace and happiness in the village. The protagonist of "A Branch Road" also returns to his rural home and is able to save his longtime beloved from a cruel husband and the drudgery of farm labor. In dozens of novels Horatio Alger Jr. writes of the "rags to riches" stories of young men from rural areas who become successful in the big city through their determination and hard work.
THE WEST AND BEYOND
Hamlin Garland echoes Alger's sentiments in his novel The Long Trail (1907), in which a young man leaves Minnesota for the Klondike. Over several months of traveling north he experiences adventures with his new prospecting friends. With hard work and determination, he makes his fortune in the Yukon gold fields and returns home a local hero. Jack London (1876–1916) also wrote of travel to the Klondike and other northern regions. The characters of "To Build a Fire" (the 1908 version), "An Odyssey of the North" (1900), and The Call of the Wild (1903) do not have the luck of the protagonist of The Long Trail. Unsuited for the harsh environment, they suffer defeat and often death in their struggles against nature.
The Great Migration, homesteading, land runs, and other large-scale internal migration are indications of the vast changes occurring in the United States during the late nineteenth century and early twentieth century. Migration literature stands as a record of the growth and power of the nation between the Civil War and World War II.
Anderson, Sherwood. Winesburg, Ohio. 1919. New York: Modern Library, 1947.
Cherokee Cavaliers: Forty Years of Cherokee History as Told in the Correspondence of the Ridge-Watie-Boudinot Family. Edited by Edward Everett Dale and Gaston Litton. Norman: University of Oklahoma Press, 1939.
Chesnutt, Charles Waddell. Tales of Conjure and the ColorLine. Mineola, N.Y.: Dover, 1998.
Douglass, Frederick. "The Future of Blacks in the United States." In "The Narrative" and Selected Writings. New York: Modern Library, 1984.
Downing, Henry F. The American Cavalryman: A LiberianRomance. 1917. College Park, Md.: McGrath, 1969.
Dreiser, Theodore. Sister Carrie. 1900. New York: Penguin, 1980.
Dunbar, Paul Laurence. The Sport of the Gods. 1901. New York: New American Library, 1999.
Garland, Hamlin. The Long Trail: A Story of the Northwest Wilderness. New York: Harper & Brothers, 1907.
Garland, Hamlin. Main-Travelled Roads. 1891. New York: New American Library, 1962.
Gilmore, F. Grant. The Problem: A Military Novel. 1915. College Park, Md.: McGrath, 1969.
Johnson, James Weldon. The Autobiography of an Ex-Colored Man. 1912. New York: Knopf, 1927.
Jones, J. McHenry. Hearts of Gold. 1896. College Park, Md.: McGrath, 1969.
London, Jack. The Call of the Wild. 1903. New York: Dutton, 1968.
London, Jack. Short Stories of Jack London: AuthorizedOne-Volume Edition. Edited by Earle Labor, Robert C. Leitz III, and I. Milo Shepard. New York: Macmillan, 1990.
Micheaux, Oscar. The Conquest: The Story of a Negro Pioneer. 1913. New York: Washington Square Press, 2003.
Micheaux, Oscar. The Homesteader. 1917. College Park, Md.: McGrath, 1969.
Taylor, Bayard. John Godfrey's Fortunes: Related by Himself; A Story of American Life. 1864. New York: Putnam, 1883.
Taylor, Bayard. Joseph and His Friend: A Story of Pennsylvania. New York: Putnam, 1871.
Twain, Mark. Adventures of Huckleberry Finn. 1885. New York: Norton, 1977.
Chandler, Alfred D., Jr. The Railroads: The Nation's First Big Business; Sources and Readings. New York: Harcourt, Brace, and World, 1965.
Cohen, William. At Freedom's Edge: Black Mobility and the Southern White Quest for Racial Control, 1861–1915. Baton Rouge: Louisiana State University Press, 1991.
Crockett, Norman L. The Black Towns. Lawrence: Regents Press of Kansas, 1979.
Glaab, Charles N. The American City: A Documentary History. Homewood, Ill.: Dorsey Press, 1963.
Greene, J. Lee. Blacks in Eden: The African American Novel's First Century. Charlottesville: University Press of Virginia, 1996.
Hoig, Stan. The Oklahoma Land Rush of 1889. Oklahoma City: Oklahoma Historical Society, 1989.
Nicodemus, Kansas. Bogue, Kans.: Nicodemus Historical Society, 1989.
Painter, Nell Irvin. Exodusters: Black Migration to Kansas after Reconstruction. New York: Knopf, 1977.
Rodgers, Lawrence R. Canaan Bound: The African-American Great Migration Novel. Urbana: University of Illinois Press, 1997.
Vincent, Theodore G. Black Power and the Garvey Movement. San Francisco: Ramparts Press, 1972.
Wiseman, Regge N. Glimpses of Late Frontier Life in New Mexico's Southern Pecos Valley: Archaeology and History at Blackdom and Seven Rivers. Santa Fe: Museum of New Mexico, 2000.
Woodson, Carter G. A Century of Negro Migration. 1918. New York: AMS Press, 1970.
Migration is a difficult concept to define because it includes people who move for different reasons across different spaces. A migrant can be a person who moves to another city or town within a nation; a refugee who crosses an international border to escape religious or political persecution; a jobseeker who moves to another country for better economic opportunities; a slave who is forcibly moved; or a person displaced by war or natural disaster. Demographers lack a single, operational definition for migration because it occurs under different conditions.
The causes of migration are related to the specific contexts in which they take place. First, the composition of migration streams are characterized by structural forces such as the global economy. Second, sociocultural differentials (gender, class, caste, etc.) have important implications for individual mobility.
Because migration occurs under different circumstances, the demographic implications for receiver populations change accordingly. For example, when large numbers of rural residents migrate to cities, infrastructure problems may arise in urban areas.
Given the variation possible in the migration process, all migrants cannot be analyzed with the same theoretical framework. However, although heterogeneous factors make a universal definition impossible, in general, migration is a process in which an individual or a group shifts their residence from one population (or place) to another. Apart from its spatial dimension, migration also implies the disruption of work, schooling, social life, and other patterns. A migrant is someone who breaks off activities and associations in one place and reorganizes their daily life in another place. A move within the same area is considered mobility, not migration, because the mover can continue day-today life (keep the same job or school, shop at the same stores, and socialize with the same people) without significant disruption (Weeks 1999).
Most demographers argue that migration must involve an essentially permanent territorial shift in residence to be distinguished from mobility. Hence, travelers and commuters are excluded from migration studies because they move across boundaries on a temporary basis and because their movement does not generally cause major change in any population. Categorizing movers strictly in terms of the permanence of their move can be problematic, however, because this method tends to disregard the social context of population movement. Temporary moves are typically absent from the census, and therefore do not register in demographic terms. In this perspective, a software engineer who makes a permanent move from San Francisco to Los Angeles is classified as a migrant, while a Mexican arriving in California as a seasonal agricultural laborer is not. However, the agricultural laborer's move is probably the most socially significant given language barriers, culture shock, and race discrimination encountered.
Just because a mover is not measured as a member of a population does not mean that their movement has had no measurable social impact on populations. Under the United States's bracero program (a system created in 1942 to help solve U.S. agricultural labor shortages), for example, the number of temporary Mexican laborers reached a point that U.S. policy makers reacted with mass deportations and the creation of a restrictive immigration act meant to keep Mexicans out. This policy created severe unemployment problems in Mexico, whose economy was not strong enough to reabsorb these workers. Hence, the program that previously encouraged mobility into the United States contributed to Mexican poverty after it was terminated in 1964. Even though they would not be counted as migrants, the mobility of Mexican agricultural workers left a deep impression on the Mexican economy, and it initiated changes to U.S. immigration policy.
Types of Migration
The relatively permanent movement of people across territorial boundaries is referred to as inmigration and out-migration, or immigration and emigration when the boundaries crossed are international. The place of in-migration or immigration is called the receiver population, and the place of out-migration or emigration is called the sender population. There are two basic types of migration studied by demographers:
- Internal migration. This refers to a change of residence within national boundaries, such as between states, provinces, cities, or municipalities. An internal migrant is someone who moves to a different administrative territory.
- International migration. This refers to change of residence over national boundaries. An international migrant is someone who moves to a different country. International migrants are further classified as legal immigrants, illegal immigrants, and refugees. Legal immigrants are those who moved with the legal permission of the receiver nation, illegal immigrants are those who moved without legal permission, and refugees are those crossed an international boundary to escape persecution.
Jay Weinstein and Vijayan Pillai (2001) denote a third classification: forced migration. Forced migration exists when a person is moved against their will (slaves), or when the move is initiated because of external factors (natural disaster or civil war). The distinction between internal and international migration is crucial because they happen for different reasons. Because structural barriers are more likely to impede the mobility of a potential international migrant than an internal migrant—international migration involves more administrative procedures, greater expense, and more difficulties associated with obtaining employment, accessing state services, learning a new language, and the like—the motivations behind international migration are usually stronger than those behind internal migration (Weeks 1999).
Theories of Migration
People move for different reasons. These differences affect the overall migration process. The conditions under which a migrant enters a receiver population can have broad implications for all parties involved. The expression migration experience refers to the fact that different causes for migration will produce different outcomes observable from a sociological perspective. For example, a person who moves within a nation will not have the same migration experience as a political refugee. In most cases, refugees need special services from the receiver population such as emergency shelter, food, and legal aid. The psychological trauma of fleeing their homeland and leaving family members behind can also complicate refugees' adjustment to their new environment. Considering that a migrant can be a slave, refugee, or job-seeker, or have some other reason for moving, no single theory can provide a comprehensive explanation for the migration process.
Although a comprehensive theory is unattainable, it remains a crucial task of demographers to explain why people migrate. Theories of migration are important because they can help us understand population movements within their wider political and economic contexts. For example, if outmigration from Third World nations is shown to be a result of economic problems caused by the global economy, then such migration could be managed with better international economic agreements instead of restrictive immigration acts. Indeed, rather than slowing Mexican in-migration to the United States, termination of the bracero program actually increased the amount of illegal immigration because it exacerbated Mexican poverty.
Ernest Ravenstein is widely regarded as the earliest migration theorist. Ravenstein, an English geographer, used census data from England and Wales to develop his "Laws of Migration" (1889). He concluded that migration was governed by a "push-pull" process; that is, unfavorable conditions in one place (oppressive laws, heavy taxation, etc.) "push" people out, and favorable conditions in an external location "pull" them out. Ravenstein's laws stated that the primary cause for migration was better external economic opportunities; the volume of migration decreases as distance increases; migration occurs in stages instead of one long move; population movements are bilateral; and migration differentials (e.g., gender, social class, age) influence a person's mobility.
Many theorists have followed in Ravenstein's footsteps, and the dominant theories in contemporary scholarship are more or less variations of his conclusions. Everett Lee (1966) reformulated Ravenstein's theory to give more emphasis to internal (or push) factors. Lee also outlined the impact that intervening obstacles have on the migration process. He argued that variables such as distance, physical and political barriers, and having dependents can impede or even prevent migration. Lee pointed out that the migration process is selective because differentials such as age, gender, and social class affect how persons respond to push-pull factors, and these conditions also shape their ability to overcome intervening obstacles. Furthermore, personal factors such as a person's education, knowledge of a potential receiver population, family ties, and the like can facilitate or retard migration.
Several theories have been developed to treat international patterns of migration on their own terms, but these too are variants of push-pull theory. First, neoclassical economic theory (Sjaastad 1962; Todaro 1969) suggests that international migration is related to the global supply and demand for labor. Nations with scarce labor supply and high demand will have high wages that pull immigrants in from nations with a surplus of labor. Second, segmented labor-market theory (Piore 1979) argues that First World economies are structured so as to require a certain level of immigration. This theory suggests that developed economies are dualistic: they have a primary market of secure, well-remunerated work and a secondary market of low-wage work. Segmented labor-market theory argues that immigrants are recruited to fill these jobs that are necessary for the overall economy to function but are avoided by the native-born population because of the poor working conditions associated with the secondary labor market. Third, world-systems theory (Sassen 1988) argues that international migration is a by-product of global capitalism. Contemporary patterns of international migration tend to be from the periphery (poor nations) to the core (rich nations) because factors associated with industrial development in the First World generated structural economic problems, and thus push factors, in the Third World.
Migration and the Family
Explanatory frameworks premised on the push-pull hypothesis tend to overemphasize the role of the individual in the migration process. Critics of this perspective argue that the decision to migrate is based on group experience, in particular the costs and benefits to the family. Rather than being an isolated calculation, an individual's decision to migrate is conditioned by multiple social and economic factors. For example, a member of a rural family may be motivated to migrate if urban employment translates into the diversification and amelioration of the family economy, or if rural productive resources are not enough to sustain an extended family. Such out-migration probably would not occur if it was likely to produce an economic deficit for the family unit. Apart from this, the decision to migrate is not calculated from an exclusively economic standpoint. An individual can have an economic opportunity in another place, but not take it up if their departure would cause emotional hardship in the sender community. In Sarah Harbison's words, the family "is the structural and functional context within which motivations and values are shaped, human capital is accrued, information is received and interpreted, and decisions are put into operation" (1981, p. 226).
The family is the crucial agent of an individual's capacity and motivation to migrate. Harbison argues that the complexities of the family structure characterize the migration process because the family unit mediates between the individual and society, and thus it can prioritize its needs over the individual's in many instances. Three factors give the family unit significant importance in the migration process (Harbison 1981; Boyd 1989).
- Because migration requires resources for transportation and to establish a new home, family support is paramount, especially because most migrants are young and lack sufficient personal savings to finance a move. In most cases, the family unit is the essential unit of economic production and thus determines the allocation of resources to individuals and specifies economic roles. Apart from the economic needs of the family, differential access to family resources and the social division of labor have important implications for individual mobility. The socioeconomic framework of the family can facilitate or restrict migration. In a situation where males control family resources, and females are assigned strict domestic roles in the division of labor, women's mobility will be structurally limited or at least determined by men.
- The family is the primary socializing unit. Through the framework of kinship, customs, values, social obligations, and the like, the family unit conditions the individual to fill a basic role in society. For example, in societies where migration is crucial for the putative well-being of the group, patterns of socialization will develop to prepare certain individuals to migrate. The primogeniture system—under which real estate passes to first-born sons—assisted the mobility of later-born sons because they were often provided an education or military placement in lieu of inheritance.
- The family is an enabling economic and social network. The geographic dispersion of kin members partially determines the migration destination. Many people move to where they have family members (rather than where economic opportunities are most fruitful) because they can be relied upon to provide food, shelter, and information, which help them cope with their new environment. The presence of kin will also reduce the psychological impact of culture shock through the perpetuation of old customs in the new place. For these reasons, ethnic groups have tended to concentrate in specific regions and neighborhoods.
Harbison (1981) points out that while the family's function as a subsistence unit, agent of socialization, and support network shapes the motivations and incentives for migration, these are also conditioned by sociocultural factors, such as marriage rules and kinship rights. Of particular importance is the gender division of labor. For the most part, migration studies have been gender-blind, and this obviously has serious implications from both a theoretical and an empirical perspective. Many studies (Bjerén 1997; Chant 1992; Kelson and DeLaet 1999) have shown that women's migration experience is fundamentally different from men's. Because gender is a primary organizing principle of the family and society, it follows that gender structures the migration process to a significant degree.
Migration and the Global Economy
Before the international economic downturns that began in the 1970s, the composition of international migration generally held to Ravenstein's hypothesis that the primary motivation for migration was economic, and that young males predominated long-distance travel. Since the 1970s, the pattern of migration has transformed with global economic changes. Moreover, the composition of migration streams transformed because earlier waves of migration created support networks that helped more recent migrants overcome intervening obstacles and difficulties associated with adjusting to a new environment (Boyd 1989). As people settled in new places, they became valuable sources of information and economic assistance for prospective migrants to draw upon. As Monica Boyd (1989) notes, while structural forces form the basic incentives for migration, push-pull factors are filtered through social networks that connect sender and receiver populations. Various patterns of migration (e.g., Mexican immigration to the United States) have become institutionalized as these networks took root.
However, while family contacts often determine where migrants move, structural forces remain powerful causal factors. Douglas Massey and colleagues (1994) point out that most empirical evidence suggests that a crucial impetus for international migration is the combination of systemic unemployment in the sender population and good employment prospects in the receiver population. World-systems theorists argue that one effect of globalization has been to keep Third World economies dependent on agriculture and the exportation of raw materials and simple commodities. Slow industrialization and relatively high fertility rates have generated acute unemployment in these nations, and this partially explains why net migration streams have generally flowed in a unilateral (from periphery to core nations) under the global economy. Economic problems associated with globalization have made labor migration an important survival strategy for many Third World families. For some nations labor has become a major export economy, and states have facilitated migration to capitalize on its economic benefits. Shu-Ju Cheng (1999) notes that there were over two million documented Filipino migrant workers worldwide by 1995, and they remitted U.S. $18 billion between 1975 and 1994. Massey and colleagues (1994) point out that Mexican remittances were so great in certain communities that there were more U.S. dollars in circulation than their peso equivalent. In 1995, the total of world remittances from migrant laborers amounted to U.S. $70 billion (Taylor 1999).
Migration connections between rural economies and urban and international labor markets are particularly important for Third World consumption and production. Out-migration from rural populations to external labor markets has stimulated consumption and productivity in many Third World countries. As Massey and colleagues (1994) note, one study of two Mexican rural communities showed that remittances from domestic urban centers and the United States sustained a level of consumption 37 percent higher than gross production therein. J. Edward Taylor (1999) remarks that for every dollar Mexican migrant laborers sent home from the United States, Mexico's Gross National Product (GNP) increased between $2.69 and $3.17. Contrary to neoclassical theory, these studies demonstrate the potential nonunitary impact of labor migration. Besides increasing household consumption, income transfers have had a dynamic impact on some Third World economies. Remittances often initiate economic improvements because they are used for productive investments, and thus increase household incomes, productivity, and the GNP.
See also:Global Citizenship; Home; Homeless Families; Immigration; Industrialization; Kinship; Poverty; Rural Families; Socialization; Socioeconomic Status; Stress; Unemployment; Urbanization; War/Political Violence; Work and Family
bjerén, g. (1997). "gender and reproduction." in international migration, immobility, and development: multidisciplinary perspectives, ed. t. hammer, g. bruch-mann, k. tomas, and t. faist. oxford, uk: berg.
boyd, m. (1989). "family and personal networks in international migration: recent developments and new agendas." international migration review 23:638–70.
chant, s., ed. (1992). gender and migration in developingcountries. london: belhaven press.
cheng, s. a. (1999). "labor migration and international sexual division of labor: a feminist perspective." in gender and immigration, ed. g. a. kelson and d. l. delaet. new york: new york university press.
harbison, s. f. (1981). "family structure and family strategy in migration decision making." in migration decision making: multidisciplinary approaches to microlevel studies in developed and developing countries, ed. g. f. dejong and r. w. gardner. new york: pergamon press.
kelson, g. a., and d. l. delaet, eds. (1999). gender andimmigration. new york: new york university press.
lee, e. (1966). "a theory of migration." demography 3:47–57.
massey, d. s.: arango, j.; hugo, g.; kouaouci, a.; pellegrino, a; and taylor, j. (1994). "an evaluation of international migration theory: the north american case." population and development review 20:699–751.
piore, m. j. (1979). birds of passage: migrant labour inindustrial societies. new york: cambridge university press.
ravenstein, e. g. (1889). "the laws of migration." journal of the royal statistical society 52:245–301.
sassen, s. (1988). the mobility of labour and capital: astudy in international investment and labour flow. cambridge, uk: cambridge university press.
sjaastad, l. a. (1962). "the costs and returns of human migration." journal of political economy 70:80–93.
taylor, j. e. (1999). "the new economics of labour migration and the role of remittances in the migration process." international migration 37:63–88.
todaro, m. p. (1969). "a model of labor migration and urban unemployment in less-developed countries." the american economic review 59:138–48.
weeks, j. r. (1999). population: an introduction to concepts and issues. boston: wadsworth.
weinstein, j., and pillai, v. k. (2001). demography: thescience of population. boston: allyn and bacon.
Migration is defined as the regular, usually seasonal, movement of all or part of a population of animals. Many different animals migrate, including birds, hoofed animals, bats, whales, seals, and salmon. One-way movement of animals that do not return is called emigration. Emigration is due to different causes and is not considered migration. Also, the regular daily movements that many animals undertake are not considered migration.
Most birds and mammals that migrate follow an annual or seasonal pattern related to cyclic variations in temperature, vegetation, or precipitation. Salmon and some other fishes do not migrate annually. Instead, they return to their place of birth in order to reproduce. Some ethologists do not consider these movements migration but reserve the term for cyclic movements. In some parts of the world, animals will suddenly move into a new area temporarily. These sudden and temporary movements are called irruptions. Irregular movements, such as irruptions, are generally due to population growth during periods of abundant food followed by dispersal when food supplies diminish.
Most migrations involve horizontal movement. Animals move north and south with the seasons or move in a circular pattern to take advantage of cyclic rain patterns or new forage growth. Some animals, however, migrate by changing elevation. Aquatic animals may move from deeper water to the surface according to the season. Many birds, mammals, and insects migrate to higher or lower elevations in mountainous areas. This kind of migration produces the same kind of change in the environment as horizontal migration but involves only small horizontal displacements.
Some shrimp and crabs migrate for purposes of reproduction. Pregnant females move into shallow water to lay their eggs. The shallow water environment has fewer large predators, so the chances of the baby shrimp growing to maturity is increased. After they mature the shrimp move into deeper water to feed.
Probably the best known insect migrant is the monarch butterfly (Danaus plexippus ). In the summer, these insects move northward as far as Canada's Hudson Bay, where they breed and reproduce. Adults from the last generation of the year migrate southward in autumn through Oklahoma and Texas. Many move as far south as the mountains of central Mexico. After overwintering in the tall firs of these mountains, they follow spring northward, breeding and laying eggs on their preferred milkweed plants. Since a few of the returning butterflies are members of the first generation that developed from the overwintered insects, they can be considered true migrators. Most insects that arrive in the north, however, have been born in route. The longest distance recorded for the complete flight of an individual monarch butterfly is 3,010 kilometers (1,870 miles), truly a remarkable flight for this tiny insect.
The three categories of migratory fishes are oceanodromous, anadromous , and catadromous . Oceanodromous fish live and migrate entirely in the ocean. The many species of herring with different migration patterns are typical of oceanodromous fish. Anadromous fish live in the sea and migrate to freshwater to breed. Pacific salmon are typical. They hatch from eggs in mountain streams or lakes. The young feed and grow in the freshwater, then migrate to the sea after a year. Adult fish usually remain in the sea for two or three winters, where they grow to full size. Then they undergo dramatic physiological changes and migrate back to the stream where they were born. There the females lay eggs that are fertilized by the males. Then both sexes die. Some Atlantic salmon breed two or three times.
Catadromous fish reverse the behavior pattern of anadromous fish. Catadromous fish spend most of their lives in freshwater, then they migrate to the sea to breed. Eels of the genus Anguilla are the best known. Both European eels and North American eels spawn in an area of the Atlantic Ocean known as the Sargasso Sea. The larval forms of the fish are carried by the Gulf Stream to the shallow waters of the continental shelves. After about two years, when the larval eels are about 8 centimeters (3 inches) long, a metamorphosis occurs. The nearly transparent free-swimming larval eels are transformed into bottom-dwelling, dark-colored, cylindrical fish. Their migration upstream is spectacular, as the young fish gather by millions, forming a dense mass several miles long. In freshwater, the eels grow to full size. They live for several years in freshwater, then undergo a final metamorphosis before they swim back to the Sargasso Sea to spawn.
Terrestrial reptiles and amphibians do not migrate regularly enough to be significant, although some species migrate vertically. Reptiles and amphibians have evolved other strategies to deal with adverse environmental conditions, such as hibernation and estivation. Sea turtles are the exception. Most sea turtles migrate to beaches to lay their eggs. They then disperse back into the ocean. Green sea turtles (Chelonia mydas ) lay their eggs on the coast of Costa Rica in Central America and then disperse through the Gulf of Mexico and the West Indies.
The taxonomic class Aves includes most of the best known migrating species. Most species of birds require a large input of food to maintain their body temperature and other behaviors. Many birds have evolved behaviors that allow them to move to areas where food is more abundant. Birds have evolved a highly efficient means for traveling swiftly over long distances with great economy of energy.
Migratory birds do not differ greatly in gross physiological characteristics from nonmigratory birds. There is a spectrum of birds from completely nonmigratory species to species that fly thousands of kilometers every year.
Since insect populations drop dramatically during the winter, insectivorous species of birds, such as warblers, flycatchers, and wagtails, are highly migratory and typically spend the winter in the tropics. The geographical arrangement of the North American continent determines migration routes for many species of North American birds. Principal routes are known as flyways. They include the Mississippi flyway, the central flyway, the Pacific flyway, and the Pacific oceanic route. Many birds spend the winter in the states that border the Gulf of Mexico, but the principal wintering areas are in Mexico and Central America. Panama has the greatest density of winter bird residents in the world.
Tropical regions do not have the four seasons of temperate regions, but they do have cyclic rainy and dry seasons. Birds of tropical regions migrate according to these wet and dry seasons.
Arctic terns (Sterna paradisaea ) are the world champion migrators. These birds breed in the coastal regions of northern Europe, Asia, and North America. They then fly south and spend the winter in the extreme southern Pacific and Atlantic along Antarctic pack ice 17,600 kilometers (10,940 miles) from their breeding range. American populations of the Arctic tern cross the Atlantic to Europe, then fly south along the coast of western Europe. Arctic terns thus travel farther than any other bird species.
Most terrestrial mammals do not migrate. True migration among terrestrial mammals occurs mostly among large hoofed animals living in habitats with wide fluctuations of climatic and biotic conditions. For example, before the central United States was largely fenced in, American bison (Bison bison ) migrated regularly. Large herds containing millions of animals moved in circular routes to the southern part of their range in winter and back north when spring rains brought fresh grass to the northern part of their range.
In North American Arctic regions, caribou (Rangifer tarandus ) regularly migrate between the open tundra, where they calve, and the forest, where they spend the winter months. In winter, each caribou herd moves independently of the other herds in response to local conditions. Then in the spring, the herds move back onto the tundra. These migrations follow the same routes from year to year.
In contrast to terrestrial mammals, marine and flying mammals typically do migrate because of their inherently greater mobility. The only true flying mammals are the many species of bats. Huge colonies of Mexican freetailed bats (Tadarida brasiliensis ) spend the summer in Texas and adjoining states. The Congress Avenue Bridge in Austin, Texas, is home to the largest urban bat colony in the world, with around 1.5 million bats. It is a huge bat nursery containing females and nursing babies, called pups. Since they are insectivorous, these bats leave around the middle of November for their winter home in Mexico. They return in mid-March when the insect population in Texas increases dramatically. Most of the females in the Congress Avenue colony give birth to a single pup in early June.
Among mammals, the marine mammals are the distance record holders. Antarctic whales, such as humpback whales (Megaptera novaeangliae ), migrate regularly to the tropics. Whales migrate to areas rich in food, particularly the northwestern coast of Africa, the Gulf of Aden, and the Bay of Bengal. Northern whales, such as blue whales (Balaenoptera musculus ), have the same migratory habits as Antarctic whales. They migrate northward along the east coast of the United States, then through Davis Strait to Baffin Bay (north of Canada) or to waters off northern Scotland or the coast of Norway.
Birds tend to follow well-defined migration routes called flyways. A population of birds may be scattered over thousands of square kilometers. As they begin their migration, the birds may be spread out over a migration front hundreds of kilometers wide. These routes are determined by geographical factors, ecological conditions, and meteorological conditions. Some routes cross oceans. American golden plover fly over open ocean from the Aleutian Islands southwest of Alaska to Hawaii, a distance of 3,300 kilometers (2,050 miles).
Many birds fly at relatively low altitudes. Hawks and other passerines, however, fly at altitudes as great as 4,000 meters (13,120 feet). The highest altitude ever recorded for migrating birds is 9,000 meters (29,520 feet) for geese near Dehra Dun in northwest India.
Some birds fly nonstop. Others are diurnal , flying during daylight hours and resting at night. Pelicans, storks, birds of prey, swifts, swallows, and finches migrate during daylight hours. Other birds reverse the pattern. Cuckoos, flycatchers, thrushes, warblers, orioles, and buntings fly at night and rest during the daylight hours.
Most birds abandon their instinctive territoriality during migration. Even unrelated birds with similar habits sometimes travel together. Some birds migrate in large flocks. Geese, ducks, pelicans, and cranes fly in well-known V-shaped formations that allow each bird to receive lift from the bird just in front.
Finding Their Way
Animals use several different techniques to navigate while migrating or to locate the place of their birth. Experiments have demonstrated the ability of animals to orient themselves geographically. Starlings have returned to their nests after being moved 800 kilometers (500 miles) away; swallows have found their way home from more than 1,800 kilometers (1,120 miles). A Manx shearwater (Puffinus puffinus ) flew 4,900 kilometers (3,040 miles) across the Atlantic from Massachusetts to Britain in twelve days. Laysan albatrosses (Diomedea immutabilis ) found their way back to Midway Island in the Pacific after being released at Whidbey Island, Washington. The journey covered 5,100 kilometers (3,170 miles) and took ten days. Experiments with fish and mammals have demonstrated similar homing ability.
Some homing animals use landmarks. The use of landmarks, however, cannot explain how migrants find their way along routes covering many hundreds or thousands of kilometers.
Birds apparently possess a compass sense. This sense is probably related to a sensitivity to Earth's magnetic field. When homing pigeons were released with tiny magnets attached to their necks, they were unable to navigate. Experiments have also shown that the orientation of birds is partly based on celestial bearings. In one well-known experiment, indigo buntings were placed in compartments in a planetarium and shown star patterns. Scratch marks on sensitive paper showed that the birds attempted to move "north" according to the star patterns displayed on the dome of the planetarium.
Experiments have shown that salmon and similar fish apparently use Sun orientation while at sea to find their way back to the general area of the stream in which they hatched. Once in the correct general area, salmon apparently use their sense of smell to locate their home waters.
What Triggers Migration?
Migration is part of the life cycle of animals. Metabolic patterns usually change prior to migration, and fats accumulate in the body tissues. Food consumption increases in the autumn reaching a peak at the beginning of the migration season. These fundamental physiological changes are apparently controlled indirectly by the pituitary gland. The pituitary acts as a sort of internal clock. Variations in temperature and hours of daylight are detected by the pituitary gland. The pituitary then influences the development of gonads and all other metabolic processes, including the thyroid gland. The thyroid gland excretes the chemical substances that cause the physiological changes that prepare the animal for migration. The pituitary serves only to prepare the animal for migration. Actual migration is triggered by appropriate environmental conditions, such as precipitation, availability of food, temperature, and weather conditions. A sudden period of cold weather during autumn may induce the immediate departure of many migrants.
Evolution and Ecology of Migration
Migration as a behavior among birds and mammals probably appeared gradually. Erratic dispersals were probably the precursors of true migration. Such erratic dispersal would have led to greater survival rates and reproductive success among animals that moved to the most favorable places. These originally erratic movements gradually acquired stability through natural selection . In some cases, original habitats were in presentday wintering areas, and animals developed a tendency to leave in spring in order to breed in other territories. Seasonal changes of weather and food supply in these newly settled regions forced the animals to migrate in fall, and they thus retreated to their former range. Many birds now nesting in the Northern Hemisphere, such as hummingbirds, tyrant flycatchers, tanagers, orioles, and swifts, have distinct tropical characteristics. These birds may have gradually spread northward as glacial ice receded.
The evolution of migration must be related to the ecological significance of migration. Migration allows fast-moving animals to exploit variations in resources and to move into areas where they could not remain year-round without the ability to move rapidly. Exploitation of peaks of food production, such as the dramatic increase of insect populations in temperate regions in the springtime, would not be possible without migratory populations.
see also Habitat.
Billington, Elizabeth T. Understanding Ecology. New York: F. Warne, 1971.
Curtis, Helena, and N. Sue Barnes. Biology, 5th ed. New York: Worth Publishing, 1989.
Miller, G. Tyler, Jr. Living in the Environment, 6th ed. Belmont, CA: Wadsworth, 1990.
Orr, Robert T. Animals in Migration. New York: Macmillan, 1970.
Purves, William K., and Gordon H. Orians. Life: The Science of Biology. Sunderland, MA: Sinauer, 1987.
Schmidt-Koenig, Klaus. Migration and Homing in Animals. New York: Springer-Verlag, 1975.
Swingland, Ian R., and Paul J. Greenwood, eds. The Ecology of Animal Movement. Oxfordshire, U.K.: Clarendon Press, 1983.
Terborgh, John. Where Have All the Birds Gone? Essays on the Biology and Conservation of Birds that Migrate to the American Tropics. Princeton, NJ: Princeton University Press, 1989.
Mexican free-tailed bats are among North America's most important animals, from both an ecological and agricultural standpoint. They consume phenomenal volumes of insects nightly, a large number of which are agricultural pests. Serious bat population decline has been observed, largely due to human activities (i.e., the destruction of old buildings or the use of pesticide) and vandalism of important roosting habitats
Migrations are mass movements from an unfavorable to a favorable locality and in plains-dwelling, large herbivores such as reindeer, bison, zebras, wildebeest, or elk they can be quite spectacular. In large sea mammals migrations are no less important, but to us are merely less visible and it has taken much effort by science to document at least a part of their extent, leaving much that is still shrouded in mystery. Mass-migrations occur when individuals flood to distant birthing or breeding grounds, to seasonal food sources, or to escape winter storms. Close associations of large numbers of individuals during migration is merely a security measure, capturing the great advantages of the "selfish herd" against predation. Long distance movements are also undertaken by individuals or by small groups, particularly in the oceans.
Migrations take their origin in minor seasonal movements between habitats, such as the movements by mountainedwelling
deer, elk, or moose between winter ranges at low elevations and summer ranges at high elevations. By moving to lower elevations in fall the deer avoid the high snow levels that develop on their summer ranges at high elevation in late fall and winter. High snow levels hamper movements, at times severely. Also, at high elevations plants, and therefore food density per unit, are low. When high snow levels hamper mobility as well as increase the cost of locomotion, feeding in areas with low food density is uneconomical and individuals move to where there is more food, preferably such that can be acquired with little cost. Movement to lower elevations
is the answer because forage density is higher and the cost of locomotion between mouthfuls of vegetation is much less. There is a high cost to scraping away snow from the forage it covers, and snow removal is easier and needs to be done less often at low elevations, at localities often out-side the mountains. A fourth factor is the shelter provided by trees and forests in winter, which are more likely to grow in valleys than on high slopes and mountain tops. Nevertheless, there is no rule without its exceptions! In the high mountains of western Canada and Alaska, once the snow hardens in late winter and its crust can support the weight of herbivores, mountain caribou and black-tailed deer may ascend the mountains and feed in the sub-alpine coniferous forests on the now accessible tree lichens. Mountain sheep and mountain goats may also ascend in order to feed on high alpine ridges where the powerful winds have blown away the snow, exposing the short, scattered, but highly nutritious grasses, sedges, and dwarf shrubs. Here the packed snow allows them to roam far and wide, be it in search of forage or to escape the occasional visit by wolves or wolverines. Also, some bull elk and bull moose may opt to stay, usually widely dispersed, at high elevation in very deep, loose snow along creeks because wolves are very unlikely to reach or harm them under such snow conditions. When hard "sun crusts" develop on the snow in late winter, however, the tables may be turned temporarily. Wolf packs can then travel freely on
the crusted snow surfaces during the night. During the day "sun crusts" may soften, trapping all travelers temporarily in deep snow.
Elevation draws herbivores into seasonal movement and change of venue by the fact that vegetation sprouts in spring
at low elevation and that this sprouting creeps upward as spring progresses. Herbivores follow this line of sprouting vegetation because sprouting vegetation it is the most nutritious and most easily digested forage there is. Consequently, there are movements by all sort of large herbivores from the valley to the mountain tops in spring and summer. Less dramatic, but equally important are the movements of herbivores in response to flooding in river valleys and the withdrawal of the flood because the areas just flooded have been fertilized with silt, and rich plant growth follows the withdrawal of water.
Migrations can become more complex if special nutritional needs must be met, or if social factors intervene into the movement pattern. American mountain sheep illustrate this well, because interspersed into the long seasonal movements between summer and winter ranges are extended visits to mineral licks in spring, to separate socializing areas of males in fall and again in spring where they meet and interact socially, and to special birthing and child-rearing areas for female sheep. These localities of increased social interaction have a powerful pull on the males, just as the lambing and lamb-rearing areas have as strong pull on females. Consequently, males and females move and live separately for all of the year except for about a month during the mating season. Mating occurs on the core wintering areas of females, which the adult males leave right after mating, possibly so as not to compete for the limited food supply available to the mothers of their prospective offspring. Thus the males move to separate wintering areas of their own. The distances between seasonal
ranges for mountain sheep may be tens of miles (kilometers) apart.
Megaherbivores such as elephants, rhinos, and giraffes may move over huge annual home ranges between small dry season ranges close to water and large wet season ranges. The size of these ranges may be hundreds of square miles (kilometers). Areas within are used opportunistically depending on forage and water availability. The ability to move rapidly over long distances, coupled with excellent memory of locations, allows elephants to live in vast desert areas. While the wet season areas are large, travel may be restricted at that time by the abundance of food. Movement may be more extensive in the dry seasons due to decreased forage density.
Food availability also dictates mass movements of African plains animals such as zebras, wildebeest, and gazelles in the Serengeti plains. The great productivity of the plains during the wet season attracts them, and they leave the woodlands they use during the dry season. Zebras, wildebeest, and gazelles form a grazing succession in which the zebras first remove the coarse grasses. The re-growth of grasses then creates good foraging conditions for wildebeest, which in turn graze down the grass exposing dicotyledonous plants that attract gazelles. The variations in timing of the rainy seasons thus affect the mass-movements of these herbivores to and from the woodlands.
Migrations are most spectacular when masses of animals unite in closely coordinated movements. As indicated earlier, the proximity of individuals to one another and the coordination that keeps them together arise as an anti-predator adaptation in species adapted to open landscapes—be they coverless terrestrial terrain or open oceans. In cover there is little possibility of group cohesion, but great opportunity for individual hiding and thus escape from predators. In the open, uniting into large formations has powerful advantages for prey. Joining with others of one's kind is a purely selfish act aimed at self-preservation. Consequently, this grouping has been labeled "the selfish herd." It is very common. To begin with, close herding empties the landscape of the species, forcing resident predators on alternate prey—except where the species is bunched. Here the chances of any individual being taken by a predator depend on the number of others of its kind it is with. In a larger herd the chances of being attacked are smaller than in a small herd. This is called the dilution effect. Thirdly, the individuals in the center of the herd are shielded from predator attacks by individuals on the periphery. This is the position effect. Fourthly, when a herd flees there is for each individual a greater chance in a large herd than in a small herd that someone is a slower
runner. Selfish herds are thus dangerous places for slow runners, be they ill or merely heavily pregnant. However, for a healthy individual of average abilities, joining with others and staying close together is an excellent way to minimize the risk of being caught by predators. As a consequence, uniting into huge herds is a possibility in large expanses of open landscape.
However, the very gathering into a huge mass raises severe problems in food acquisition. A large mass of herbivores will quickly deplete the available forage and must move on. That is, huge herds must move just to stay fed and it matters little where they go as long as they stay with food. This leads, of course, to unpredictable movements, which incidentally reduces predation risk still further as it does not permit predators to anticipate the direction or time of movements. This random movement, excepting predictable occupation of grasslands freed of snow in winter by warm katapatic winds along mountain fronts, or of grasslands recovering from large wildfires, was suggested to be the model of bison migration in North America up to the late nineteenth century. That is, food availability governed the mass-movements of the bison herds over the huge expanse of prairie in the center of the continent.
The mass migrations of reindeer in Eurasia and barren ground or Labrador caribou in North America have as their primary focus the calving ranges in spring. Pregnant females lead this migration, which is closely focused in both space and time. This is the most predictable migration and it leads to barren, snowed-over areas with a minimum of predators. These large, dense herds also reduce predation by "swamping" existing predators with a great surplus of calves on the calving grounds. Reindeer bulls lag behind in the migration. From the calving grounds the herds move predictably to summer ranges with high productivity and some protection from insects, which in large numbers can debilitate caribou. Males and females mix on the summer ranges. From the summer feeding grounds the herds drift towards the wintering areas below the timberline. They mate during a short rutting season while traveling to the winter ranges. Caribou can travel with remarkable speed and shift location within any seasonal range. Nevertheless, their movements are predictable as they follow the same landscape features including favorite locations above waterfalls and rapids on large rivers. These and large lakes are no serious barrier to caribou, which are excellent swimmers. Caribou may travel over 3,100 mi (5,000 km) in their annual migrations.
A feature common to migratory terrestrial or marine species is that they become very fat on their summer feeding grounds and then depart with a fat-load to subsidize their maintenance and reproductive activities elsewhere. Fattening—which is metabolically a very expensive process since for
every unit of fat stored, as much as another unit is lost as metabolic heat—evolved in response to both seasonality of climates and high diversity of habitats within any one season. Extremes in seasonality as well as in terrestrial and marine habitats developed during the major glaciations of the Ice Ages during the Pleistocene.
Some extreme examples of fattening and long distance migrations were evolved by baleen whales. For instance, in the short Antarctic summer such whales congregate about the Antarctic pack ice encircling the Antarctic continent, particularly in regions where the cold waters rich in dissolved oxygen and carbon dioxide are fertilized by mineral-rich, warm deep-current upwellings to produce explosive plankton growth. Whales feed gluttonously on this superabundant food, mainly on krill, which consist of small crustaceans, and lay down massive fat deposits. Some whales reach about 40% body fat at the end of summer. As the Antarctic summer turns to winter the pack ice extends outward from the continent, cutting off whales from their feeding grounds. The whales depart for warm waters thousands of miles (kilometers) away where the pregnant females give birth to their young and maintain lactation while usually fasting until the following summer. These whales thus live by a "boom and bust" economy and their huge size and reduced metabolism per unit mass allow them to exist without feeding through the greater part of the year. Similar patterns of seasonal feeding and dispersal are followed by whales in the Northern and Southern Hemispheres except that the plankton food supply in the Antarctic appears to be richer on average and whales reach there larger sizes. Clearly, being able to fast during the reproductive periods allows whales to choose areas of increased security for their newborn and growing offspring. The phenomenon of gigantic migratory whales is predicted on the existence of polar mineral-enriched waters near the freezing point that, unlike tropical mineral-poor waters, are superlative producers of phyto and of zooplankton, as well as on the existence of fast-freezing polar ice shelves that after summer exclude the gluttonous behemoths.
Terrestrial migration has not been for small-bodied creatures, the myth of northern lemming migrations not withstanding. Small-bodied mammals tend to deal with seasonality by growing fat in summer and hibernating during the winter, as do some northern carnivores such as bears and badgers. Hibernating is a withdrawal in time from severe climatic and foraging conditions; migration is a withdrawal in space. Thus these are both adaptations that deal with the severity of seasonal winter climates.
The presence of large, very fat herbivores must have been an irresistible attraction to human hunters for untold millennia.
To exploit such migratory species, however, requires either following them continuously—an unlikely prospect—or developing a way to regularly intercept their migrations, killing in excess of need, and finding means to store the surplus for the future. Intercepting migratory species cannot be done with out understanding chronologic time. Migrants tend to reappear in the same localities much at the same calendar time, particularly if migration is closely tied to reproduction. Reproduction is timed in some of the migrants by the annual light regime which, via stimuli through the optic nerve to the hypothalamus, regulates the hormonal orchestration of reproduction. The variation in annual reproduction tends to be narrowly confined about specific calendar dates, and so are the migratory movements associated with reproduction. The same individuals reappear in the same locality within a few days of the same calendar date each year.
There is some evidence to suggest that Upper Paleolithic people in Eurasia discovered chronologic time and used it to predict and exploit migratory reindeer. They marked what appear to be lunar calendars on tines cut from reindeer antlers. That would have enabled them to anticipate reindeer migrations, move to localities where reindeer were vulnerable, and prepare for the kill. Reindeer bones comprise over 90% of the bones from Upper Paleolithic archeological sites. There is evidence for large flint-blade processing sites. Long, very sharp flint blades were struck skillfully from large flint cores. These long, thin flint flakes are ideal knives for the many hands needed to carve up reindeer meat for drying. Wood ash, ideal for smoking and drying meat, predominates in Upper Paleolithic hearths. The pattern of bone fragments indicates that de-boning of reindeer carcasses was done away from processing sites, so that meat was brought in for processing with just the bones required to hold the meat together or those used for marrow fat or tools. The superlative physical development of these large-brained cave-painters indicates that they enjoyed abundant food of the highest quality. Caribou meat has balanced amino acids for humans and caribou fat has an optimum essential fatty acid balance for brain growth. Caribou are valued highly as food by indigenous people and Arctic travelers and their fur is unsurpassed as a material for clothing and shelters in Arctic climates. Eventually salmon replaced some of the reindeer in the Upper Paleolithic, but salmon runs are also chronologically timed and can be predicted by calendar dates. To exploit a reindeer or salmon run it is crucial to be at the right place in the right time. And the same applies to migrations of bowhead whales along the coast, an important traditional food source for northern coastal people. Without an idea of chronologic time and how to keep track of it, no large-bodied mammalian migrants could be hunted systematically. With the discovery of chronologic time, however, these very rich, predictable, high-quality food sources became available for exploitation, leading to the spread and dominance of modern humans from the late Pleistocene onward.
Geist, V. Deer of the World. Mechanicsburg, PA: Stackpole Books, 1998.
Geist, V. Mountain Sheep. A Study in Behavior and Evolution. Chicago: University of Chicago Press, 1971.
Irwin, L. L. "Migration." In North American Elk: Ecology and Management, edited by Dale E. Toweill and Jack Ward Thomas. Washington, DC: Smithsonian Institution Press, 2002.
Maddock, Linda. "The 'Migration' and Grazing Succession." In Serengeti: Dynamics of an Ecosystem, edited by A. R. E. Sinclair and M. Norton-Griffiths. Chicago: University of Chicago Press, 1979.
Owen-Smith, R. N. Megaherbivores. Cambridge: Cambridge University Press, 1988.
Slijper, E. J. Whales. Ithaca, NY: Cornell University Press, 1979.
Fancy, S. G., L. E. Pank, K. R. Whitten, and W. L. Regelin. "Seasonal Movements of Caribou in Arctic Alaska as Determined by Satellite." Canadian Journal of Zoology 67 (1989): 644–650.
Valerius Geist, PhD
During the Great Depression more than two and one-half million Americans, many of them povertystricken, took to the road. They moved from country to city and sometimes from the city back to the country, from the South to the North and from the North and South to the West, within states and from state to state, leaving one region for another, in pursuit of elusive opportunities elsewhere. Families as well as single individuals set forth with what little they had, stealing rides in boxcars, bartering their few remaining possessions to obtain gasoline for decrepit jalopies, hitchhiking down dusty highways. In general, they left areas affected by declining manufacturing output, adverse weather conditions, soil erosion, farm foreclosures, boll weevil ravages, mechanization forcing laborers off the land, and stifling racial segregation.
The trend toward interregional migration began before the Depression. Migration rates were considerably higher in the United States from 1920 to 1930 than from 1930 to 1940. In the 1920s the population of the Northeast and North Central states grew, in part because of an influx of immigrants from abroad. During the same period nativeborn migrants headed to the North and West, fleeing drought and other agricultural devastation in the middle and southern portions of the nation. African Americans left the South in response to both adverse changes in farming and legalized discrimination.
Manufacturing cutbacks of the 1930s brought net declines in population to the Northeast and North Central regions as closed factory doors prompted migration from industrialized states. At the same time migrants continued to head out of the South and the parched Dust Bowl of the Southwest where howling winds scooped up dry topsoil. With its promise of orange groves and fertile fields, California beckoned as a particularly attractive destination for some 400,000 migrants called Okies. These were farmers, blown off their land in Oklahoma and parts of Missouri, Kansas, Colorado, and Texas, who headed west on Route 66 in old automobiles.
In a 1944 report, the federal Social Security Board estimated population shifts in the United States due to migration totaled more than 5,800,000 from 1920 to 1930. This figure was cut nearly in half during the Depression, with the comparable estimate given as 2,576,000. Nevertheless, the fact that migration remained significant from 1930 to 1940 showed that thousands of Americans saw no way to improve their plight except to move.
Different and confusing names characterized those who crossed state lines looking for work from 1930 to 1940. Initially, interstate migrants were somewhat differentiated from seasonal migrant laborers who traditionally had moved from place to place to harvest crops. In the early days of the Depression, those on the road commonly were called transients. They also were referred to by such terms as nonresident indigents or the unattached. Sometimes they were lumped together with hobos and tramps, social outcasts who were long-term wanderers.
When the New Deal pushed through its Federal Emergency Relief Act in May 1933, it contained provision for a Federal Transient Program to help those who had left their homes. The program lasted for two years, functioned in forty-four states, and, at its height, offered assistance to more than 300,000 persons. It ended when the Roosevelt administration changed its approach to relief from direct aid to work-oriented projects centered in local communities. This left the floating population without legal rights to benefits, although the Resettlement Administration (which became part of the Farm Security Administration in 1937) provided some camps for migrants.
As the 1930s unfolded, the term migrant was used increasingly in place of the word transient. In 1940 the U.S. House of Representatives looked into the problems facing migrants. Its Select Committee to Investigate the Interstate Migration of Destitute Citizens held hearings from New York to California. Its five hundred witnesses dealt with deplorable conditions faced by transients, some of whom had become migratory agricultural workers. The hearings had little impact on legislation because the advent of World War II ended mass unemployment, but the committee's work made it plain that migration was changing the face of the United States.
The 1944 Social Security Board report provided a statistical picture of migration within the United States for the two decades prior to World War II. It pointed out that twenty-one states and the District of Columbia gained population from 1930 to 1940, acquiring a total of 2,567,000 new residents due to migration. At the same time the majority of states, twenty-seven, lost population as residents left to seek improved circumstances. In the early years of the Depression, migration in the Northeast took place from large cities and industrial areas, where workers had lost their jobs, to selected agricultural areas where migrants hoped to be self-sufficient. This trend shifted back somewhat toward the end of the decade with improvements in business and industrial conditions.
During the 1930s the industrialized Northeast and the North Central states lost population, as did most of the South with the exception of Florida. Virginia and Maryland grew in population, benefiting from the expansion of government employment in the neighboring District of Columbia. But it was the West, including both the mountain and Pacific states, that scored the biggest increase, adding a total of 1,322,000 residents. California alone gained l,052,000 residents during the 1930s. Figures included both foreign-born and native persons, although immigration into the United States and emigration from it offset each other from 1930 to 1940. This contrasted with the previous decade when immigrants from abroad played a pronounced role in population growth. Clearly, during the Depression, when birth rates were particularly low, states that gained population did so due to interregional migration.
From 1930 to 1940 relatively modest migration increased the population of New Hampshire, Connecticut, Indiana, Minnesota, Delaware, Virginia, Tennessee, Louisiana, Texas, Idaho, Wyoming, Colorado, New Mexico, Arizona, and Nevada. Many of these states served as magnets for the unemployed from industrial areas. Only a few states added more than 100,000 individuals. These included Maryland, Oregon, and Washington, along with the District of Columbia. Florida attracted 334,960 new residents by the end of the decade.
With some exceptions these migratory trends represented a continuation of patterns already in place. The nine states that had the largest gains in population from 1930 to 1940—California, Oregon, Washington, Nevada, Arizona, Indiana, Connecticut, Maryland, and Florida—also had the largest increases in the preceding decade (from 1920 to 1930). While the annual rate of migration to these states declined during the Depression, it picked up again during World War II. From 1920 through 1940 a total of twenty states had continuous losses in population—Maine, Vermont, Pennsylvania, North Carolina, South Carolina, Georgia, Alabama, Mississippi, Arkansas, Kentucky, West Virginia, Iowa, Missouri, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, Wisconsin, and Montana; this trend also continued into World War II.
The Depression slowed, but did not stem, the general movement of African Americans from the South to the North and from rural to more urban areas within Southern states. Journalist Lorena Hickok, an undercover investigator of Depression conditions for the Roosevelt administration, noted the latter phenomena. She reported that white Southerners claimed that New Deal relief programs drew low-paid agricultural workers, many of them African Americans, out of the cotton fields and into nearby cities where they found little employment. More to the point, many white planters pocketed money paid to them by Roosevelt's Agricultural Adjustment Administration for taking land out of production. By refusing to share payments with their tenants and sharecroppers, as they were supposed to do, planters forced them off the land. In some cases they replaced laborers with machinery. Thus, the New Deal unwittingly contributed to displacements that encouraged migration already underway.
Nearly 500,000 African Americans fled the South from 1910 to 1920 when jobs opened to them in northern industry. The following decade an additional 750,000 exited to escape harsh economic and social conditions. During the 1930s the South lost about 350,000 African Americans, less than half the previous decade's total. The mass exodus of African Americans from the South did not come until the 1940s and 1950s when about three million people moved North and West, initially drawn by work in World War II defense plants. Nevertheless, the Depression did not halt redistribution of the African-American population outside the South, a movement that led to sweeping political changes and the end of segregation.
No group of migrants captured the feel of the Depression in the popular imagination to as great an extent as the Okies. The documentary photographer Dorothea Lange took a widely reproduced picture of a toil-worn Okie mother and her hungry children. Titled "Migrant Mother," it appeared in An American Exodus: A Record of Human Erosion (1939), a book written by Lange and her husband, economist Paul Taylor. Lange's photograph still is used to symbolize the destitution faced by millions during the 1930s.
John Steinbeck's best-selling novel The Grapes of Wrath (1939), subsequently made into a popular movie, familiarized the nation with the tribulations of the penniless Joad family as they strove to find a new life in California. The Joad family's fictional travails represented those of thousands of uprooted individuals who tried to better themselves by moving. Although many eventually established themselves in their new surroundings, the chronicles of downtrodden migrants in the 1930s remain a heartwrenching part of American history.
Asch, Nathan. "Cross-Country Bus." New Republic 87 (April 25, 1934): 301–304.
Committee on Care of Transient and Homeless. Records of the National Urban League. Part I. Series 4, Box 3, Manuscript Division, Library of Congress, Washington, D.C.
Conrad, David E. The Forgotten Farmers: The Story of Sharecroppers in the New Deal. 1965.
Kennedy, David M. Freedom from Fear: The American People in Depression and War, 1929–1945. 1999.
Lange, Dorothea. "The Making of a Documentary Photographer." Oral history interview with Suzanne Riess. University of California Regional Oral History Office, Berkeley, 1968.
Lisca, Peter. John Steinbeck: Nature and Myth. 1978.
Lowitt, Richard, and Maurine Beasley, eds. One Third of a Nation: Lorena Hickok Reports the Great Depression. 1981.
Olson, James S., ed. Historical Dictionary of the New Deal: From Inauguration to Preparation for War. 1985.
Peeler, David P. Hope among Us Yet: Social Criticism and Social Solace in Depression America. 1987.
Shindo, Charles J. Dust Bowl Migrants in the American Imagination. 1997.
Schomburg Center for Research in Black Culture. The New York Public Library African America Desk Reference. 1999.
Smith, Jessie Carney, and Carrell Peterson Horton, eds. Historical Statistics of Black America. 1995.
Stott, William. Documentary Expression and Thirties America.1973.
Woytinsky, W. S. "Internal Migration during the War." Report prepared for the Bureau of Employment Security, Social Security Board. Records of the National Urban League, Part I. Series 3, Box 18, Manuscript Division, Library of Congress, Washington, D.C.
Maurine H. Beasley
Migration is the act of moving from one place to another, and is often associated with seasonal movements of animals between their breeding territory and a wintering range. This activity is most readily observed in birds, but has been documented in many other animals as well, including insects, fish, whales, and other mammals. Migration is a complex behavior that involves timing, navigation and other survival skills.
The migration behaviors of different species of animals can be categorized as either complete, partial, differential, or irruptive. In complete migration, all of the members of a population will travel away from their breeding habitat at the end of that season, often to a wintering site hundreds or even thousands of kilometers away. The arctic tern (Sterna paradisaea) is an example of a complete migrant. Individuals of this species travel from the arctic to the antarctic and back again during the course of a year, a round-trip migration of more than 18,600 mi (30,000 km).
In other species, some individuals will remain at the breeding ground year round, while other members of the same species migrate away. These species are called partial migrants. American robins (Turdus migratorius), considered indicators of spring in some areas, are year-round residents in others.
Differential migration occurs when all the members of a population migrate, but not necessarily at the same time or for the same distance. The differences are often based on age or sex. Herring gulls (Larus argentatus), for example, migrate a shorter and shorter distance as they grow older. Male American kestrels (Falco sparverius) spend more time at their breeding grounds than do females, and when they do migrate, they do not travel as far.
Irruptive migration occurs in species which do not migrate at all during some years, but may do so during other years, when the winter is particularly cold or food particularly scarce. For example, some populations of blue jays (Cyanocitta cristata) are believed to migrate only when their winter food of acorns is scarce.
Migration is usually thought of as a southward movement in autumn and a return northward in the spring. These migrations, termed latitudinal migrations, are the most common type, but there are several other directions in which migratory animals may travel. A mirror image of latitudinal migration, often called austral migration, occurs in the Southern Hemisphere. These migrations tend to be shorter than those in the Northern Hemisphere, mainly because of the scarcity of land in the cold regions of the Southern Hemisphere.
Some birds, such as prairiefalcons (Falco mexicanus), travel east to west and back. These movements, called longitudinal migrations, are probably related to seasonal changes in the choice of prey and its location.
Elevational migration occurs in many animals that live on mountains. A short migration to lower elevations in winter will accomplish the same as a much longer southerly migration, since valleys have warmer climates than do mountaintops. A form of elevational migration also occurs in zooplankton, tiny animals that drift with the currents in the open ocean. In the summer, when tiny plants are abundant, the zooplankton live near the ocean surface, feeding on the plants. In the winter, they migrate 1,090 yd (1,000 m) deeper and do not feed at all.
Migratory animals travel along the same general routes each year. Several common “flyways” are used by North American birds on their southward journey. The most commonly used path includes a 496-682 mi (800-1,100 m) flight across the Gulf of Mexico. In order to survive this arduous journey, birds must store extra energy in the form of fat. All along the migration route, but particularly before crossing a large expanse of water, birds will rest and eat, sometimes for days at a time. The recommencement of the journey will begin only when a certain amount of body fat is reached.
The requirement of stopover sites in addition to breeding and wintering sites makes migratory animals particularly susceptible to habitat loss, and thus many migrants are among our most endangered species.
Although most migrants travel at night, a few birds prefer daytime migrations. The pathways used by these birds tend to be less direct and slower than those of night migrants, primarily because of differences in feeding strategies. Night migrants can spend the day in one area, foraging for food and building up energy reserves for the night’s non-stop flight. Daytime migrants must combine travel with foraging, and thus tend to keep to the shorelines, which are rich in insect life, capturing food during a slow but ever-southward journey.
Despite the dangers of long-distance travel, many different animals have developed migration strategies, presumably as a defense against the greater dangers of environmental uncertainty and competition. The breeding range of migratory animals is likely to cover a region whose environment becomes increasingly inhospitable after the breeding season is over (i.e. there is less food available in the winter), so it is advantageous to travel elsewhere. The wintering ranges will have food available year-round, but also many more animals competing for that food, as well as increased competition for shelter in which to raise their young. Hence the advantage of returning to the breeding grounds, where competition is less severe.
Perhaps the most remarkable aspect of migration is the navigational skills employed by the animals. Birds such as the albatross (Diomedea sp.) and lesser golden plover (Pluvialis dominica) travel hundreds of miles over the featureless open ocean, yet unerringly
Habitat— The place that an animal lives, which provides everything necessary for the animal’s survival.
Navigation— The process of finding one’s way to a known destination across unfamiliar terrain.
home in on the same breeding grounds year after year. Salmon (Oncorynchus sp.) migrate upstream from the sea to the very same freshwater shallows in which they were hatched. Monarch butterflies (Danas plexippus), which began life in the United States or Canada, travel to the same wintering grounds in southern California or Mexico that had been used by ancestors many generations removed.
How are these incredible feats of navigation accomplished? Different animals have been shown to use a diverse range of navigational aids, involving senses often much more acute than our own. Sight, for example, may be important for some animals’ navigational skills, although it may often be secondary to other senses. Salmon can smell the water of their home rivers, and follow this scent all the way from the sea. Pigeons also sense wind-borne odors and may be able to organize the memories of the sources of these smells in a kind of internal map. It has been shown that many animals have the ability to sense the magnetic forces associated with the north and south poles, and thus have their own built-in compass. This magnetic sense, along with the sense of smell, are believed to be the most important factors involved in animal migration, but researchers are continually discovering new and unusual navigational systems throughout the animal kingdom.
Baker, Robin, ed. The Mystery of Migration. New York: The Viking Press, 1981.
Halliday, Tim, ed. Animal Behavior. Norman, OK: Univ. of Oklahoma Press, 1994.
Long, Michael E. “Secrets of Animal Navigation.” National Geographic 179, no. 6. (June 1991).
National Center for Ecological Analysis and Synthesis. “Migration Patterns” <http://www.nceas.ucsb.edu/nceas-web/kids/mmp/migration.htm> (accessed December 2, 2006).
David E. Fontes
migration of animals
migration of animals, movements of animals in large numbers from one place to another. In modern usage the term is usually restricted to regular, periodic movements of populations away from and back to their place of origin. A single round trip may take the entire lifetime of an individual, as with the Pacific salmon; or an individual may make the same trip repeatedly, as with many of the migratory birds and mammals. The animals may travel in groups along well-defined routes; or individuals may travel separately, congregating for breeding and then spreading out over a wide feeding area, as do some of the seals.
Types of Migration
Seasonal migrations occur in many species of insects, birds, marine mammals, and large herbivorous mammals. These migrations often provide the animals with more favorable conditions of temperature, food, or water. Many birds and a few bats of cold and temperate regions migrate to warmer areas during the winter. Herbivores of cold regions, such as wapiti (elk), caribou, and moose, have summer and winter ranges; many herbivores of warm regions, such as the African antelopes, migrate seasonally to avoid drought. These migrations may involve a change of latitude, of altitude, or both.
In many cases the chief function of seasonal migration is to provide a suitable place for reproduction, which may not be the place most suitable for the feeding and other daily activities of adults. Hundreds of thousands of gnus (wildebeests) of E Africa take part in annual migrations to calving grounds. Many fishes migrate to spawning grounds, and in some cases this involves a change from saltwater to freshwater (e.g., salmon) or vice versa (e.g., freshwater eels). Sea turtles, seals, and many sea birds come ashore to breed, and most amphibians gather near water at the breeding season. Fur seals and many whales make ocean voyages of thousands of miles to their breeding grounds, the former coming ashore on islands. Such migration is seriously affected by the increasing rate of destruction of natural habitats.
The term emigration refers to irregular movements out of an area, with no return. When such emigration is the result of sudden, explosive population increase, it is called an irruption. Irruptions are common among small rodents, notably lemmings, and various species of birds and insects. The mass movements of the so-called migratory locusts of N Africa (Locusta) and North America (Melanoplus) are actually irruptions; however, the N African desert locust (Schistocerca) makes true migrations between its winter and summer breeding grounds.
Another type of one-way travel is the regular dispersal of the young of most species. The simplest type of regular migration is the diurnal movement of some marine microorganisms from one depth to another in response to light changes. Certain marine invertebrates, such as the palolo worm (see Annelida), have a monthly migration pattern influenced by the phases of the moon.
Initiation of Migration
Various factors determine the initiation of migration. In some cases external pressures—temperature, drought, food shortage—alone may cause the animals to seek better conditions. For example, most of the mule deer of Yellowstone Park, Wyo., migrate between summer and winter pastures, but those living near hot springs, where grazing is available all year, do not. In many species migration is initiated by a combination of physiological and external stimuli. In birds the migratory instinct is related to the cycle of enlargement of the reproductive organs in spring and their reduction in fall. Experiments have shown that variation in day length is the chief external stimulus for this cycle: light received by the eye affects production of a hormone by the anterior pituitary gland, which stimulates growth of the reproductive organs.
Orientation and Navigation
Much work has been done on orientation and navigation in migrating animals, although the subject is still not well understood. Studies of salmon indicate that they depend on the olfactory sense to locate and return to their stream of origin. Herbivorous mammals often follow well-established trails and probably also use their sense of smell. Bats, whales, and seals use echolocation to navigate in the dark or underwater; in addition, some whales appear to take visual bearings on objects on the shore in their migrations.
Migratory birds are believed to use the stars, sun, and geographic features as guides. The probability that stellar navigation is used has been strengthened by experiments in planetariums indicating that birds navigate at least in part by the stars. Night-migrating birds are sometimes disoriented in prolonged heavy fog. Day-flying birds navigate by the sun and also make some use of geographic features, particularly of shorelines. Many birds also have the ability to orient themselves to the earth's magnetic fields and this appears to contribute to their ability to navigate, but the mechanisms by which this happens are not well understood. Most migratory birds travel within broad north-south air routes known as flyways. There are four major flyways in North America, called the Pacific, central, Mississippi, and Atlantic flyways. The space within the flyway used by a particular group of birds is called a corridor. Bird migration is not always in a north-south direction. Many European birds migrate in an east-west direction, wintering in the more temperate British Isles, and many mountain-dwelling birds descend to lower altitudes in winter. The breeding grounds of a bird species are regarded as its home territory. Some migratory birds winter only a few hundred miles from their breeding grounds, while others migrate between the cold or temperate zones of the two hemispheres. The longest journey is made by the arctic tern, which alternates between the Arctic and the Antarctic.
The monarch butterfly has a north-south migration pattern that resembles that of many birds. One monarch population that inhabits northeastern and midwestern North America averages c.12 mph (19 kph) as it heads for the winter to Mexico's Sierra Madre mountains. Monarchs start the return trip in the spring, but they breed along the way and then die; the new generation completes the journey. Studies suggest that monarchs are able to use both the sun and the direction of the earth's magnetic field to navigate.
Tools for Studying Migration
The movements of migrating animals are often studied by tagging individuals. Bird banding has been carried on extensively since the 1920s; more recently there has been tagging of fishes, butterflies, and marine mammals. Use is now made of radar, sonar, and radio for following migrations, particularly those of marine animals. Radio transmitters attached to whales or seals emit signals that can be picked up by weather satellites at regular intervals.
See R. R. Baher, The Evolutionary Ecology of Animal Migration (1978); D. J. Aidley, Animal Migration (1981).