SOCIAL MOBILITY

Social mobility is the movement of individuals or other social units between social statuses and positions. This mobility can be between the status of individuals and that of their forbears or their offspring ("intergenerational" mobility), or between different statuses of individuals within their own lifetimes ("intragenerational" mobility). The study of social mobility focuses on movement between occupations or, to a lesser extent, on changes in status signaled by income, wealth, poverty, or educational attainment. In principle, however, social mobility encompasses a wider set of social and cultural traits, such as family structure, religious affiliation, language, and political party identification.

Most modern research on social mobility focuses on the conceptualization, measurement, and description of mobility patterns at the national level for a variety of countries and periods. Motivated by an effort to examine the "openness" or "rigidity" of systems of social stratification and inequality, the study of mobility is part of the analysis of population composition. Social mobility, however, is also linked to dynamic aspects of demography because of its interdependence with basic demographic processes at both the individual and population levels.

Measurement and Analysis of Social Mobility

Research on social mobility focuses on either bivariate or multivariate relationships between dimensions of social position. Bivariate analyses of occupational mobility typically compare individuals by their occupational categories at their places of social origin and destination. The classification of occupations may be highly aggregated, focusing on only a small number of analytically important categories, or disaggregated to detailed occupations. Analytical categories may emphasize a general socioeconomic hierarchy or follow more relational, nonhierarchical class schemes. Regardless of the type of occupational classification, mobility analyses focus on the patterns of association between origins and destinations.

In the context of intergenerational occupational mobility, patterns include the degree to which offspring occupy the same social positions as their parents and, for those who are in different locations from those of their parents, whether flows between particular combinations of discrepant origins and destinations are unusually large or small. Using modern methods of categorical data analysis applied to mobility tables, researchers investigate the complex patterns of associations between origins and destinations. A cross tabulation of individuals by their origins and destinations is affected by the relative numbers of persons in the various categories of origins and destinations considered separately–the "marginal distributions" of the mobility table–and the associations between origins and destinations. Some degree of mobility may occur simply because the relative numbers of persons in origin positions differ from the relative numbers in destination positions. This mobility is often termed "structural mobility" because it is interpreted as resulting from changes in the occupational structure. Even in the absence of change in the occupational structure, however, substantial mobility typically occurs because of a certain degree of openness in a society. This mobility is termed "exchange," "circulation," or "relative" mobility.

A common focus of mobility analyses is to compare mobility patterns across populations and to discern the degree to which differences result from variation in the changes between the origin and destination marginal distributions, and which result from variation in the associations between origin and destination once the marginal distributions have been statistically controlled. In most Western societies during the twentieth century, secular changes in occupational mobility were mainly the result of changes in the distribution of occupations. These changes resulted from the shrinkage of agriculture, the shift from a manual to a largely non-manual workforce, and the shift from an industrial to a service economy. In comparison to these large changes in structural mobility, fluctuations in exchange or circulation mobility have been modest. Similarly, occupational mobility variations among industrial societies are mainly attributable to variations in occupational structure per se rather than crossnational variations in the net association between social origins and destinations.

The theoretical distinction between structural and circulation mobility, however, corresponds only roughly to the empirical distinction between marginal and associational variations in intergenerational mobility tables. The two marginal distributions of a social mobility table cannot both correspond directly to occupational structures at two points in time. For example, in mobility data derived from a cross-section survey of adult offspring, the destination marginal of the table does represent the occupational structure at the time of survey. The origin marginal of the table, however, does not represent the occupational structure at any single point in time because of variations in the timing of fertility among parents. Moreover, the relative numbers of parents in different occupation categories are affected by differentials in the level of fertility by parents' occupation, as well as by the occupational structures that prevailed during the periods when they raised their offspring.

Multivariate analyses of social mobility follow two general strategies. One is to examine the processes through which the statuses of social origins affect the statuses of destinations by identifying variables and statistical relationships that intervene between characteristics of parents and those of their adult offspring. These analyses typically focus on scalar measures, such as occupational status, years of school completed, earnings, and number of siblings, and attempt to isolate the direct and indirect effects of antecedent statuses on adult outcomes. For example, the gross effect of parent's occupational status on offspring's occupational status is attributable in part to the smaller average number of children born to higher status parents, the higher level of education acquired by offspring in such families, and the advantages that higher levels of education and fewer siblings bring to adult achievement. In most industrial and postindustrial societies, educational attainment plays a pivotal role in social mobility and achievement. Much of the association between parent's and offspring's adult socioeconomic statuses is accounted for by the dependence of offspring's educational attainment on parents' socioeconomic position and by the strong effect of offspring's educational attainment on the offspring's own socioeconomic attainment. Across cohorts born during the twentieth century, moreover, the indirect effect of social origins on destinations via educational attainment has increased, while the direct effect of social origins net of educational attainment has decreased. A second multivariate approach to the investigation of social mobility is the direct investigation of movement between education levels, jobs, occupations, or wage levels. This approach relies on variants of event history and multivariate life table analysis and uses data on the detailed temporal sequences of statuses or positions that individuals hold. Such analyses are well suited for the description of careers and the interdependence of socioeconomic mobility and other demographic transitions, such as movement between marital and childbearing statuses.

Social Mobility and Population Renewal

Social mobility is linked to population renewal in a variety of ways at the individual, family, and aggregate population levels. A longstanding concern of demographers is the potential impact of intergenerational social mobility on the fertility of women. The social mobility hypothesis suggests that upwardly mobile individuals may have unusually low fertility because low fertility may facilitate career success and wealth accumulation. Rigorous efforts to substantiate this hypothesis, however, have been largely negative, showing that apparent mobility effects are largely reducible to the effects of fertility norms specific to a woman's socioeconomic origin and to her destination rather than to social mobility per se. In contrast, a much better established relationship is a negative effect of fertility in the family of orientation–that is, number of siblings–on adult socioeconomic success. This relationship occurs because number of siblings indexes the degree of dilution of the economic, social, and psychological resources that parents provide their children. It holds for most Western societies, even when multiple indicators of parental socioeconomic background and family structure are controlled. Exceptions to the generally negative effect of number of siblings, however, occur in populations in which larger kin networks provide a socioeconomic advantage.

At the aggregate level, social mobility is a key mechanism through which fertility, marriage, and immigration may affect population composition. The classic model of population renewal assumes an age-differentiated but otherwise homogeneous onesex closed population subject to age-specific rates of fertility and mortality. This model can be extended to two-sex populations, to geographically heterogeneous populations, and to populations open to immigration and emigration. When considering how population renewal affects changes in the makeup of socially differentiated populations, however, it is usually necessary to also incorporate social mobility into the models. Differential fertility of social groups defined by, for example, language, religious affiliation, educational attainment, measured intelligence, or income strata, may affect the subsequent makeup of the population in these groups. The effect of fertility differentials on population composition, however, depends on the degree to which membership in these groups is open or closed across generations. In populations in which intergenerational social mobility is low–that is, in which the correlation between parental and offspring characteristics is high–differential fertility may strongly affect the differential growth rates of social groups. Conversely, when social mobility is high, the effects of differential fertility are offset by the tendency for offspring to belong to different social groups from their parents'. Similarly, high correlations between the socioeconomic characteristics of marriage partners may create higher levels of inequality in subsequent generations because of the reinforcing effects of both variation and covariation in parents' characteristics on inequality among their children. The inequality-producing effects of assortative marriage, however, may be nullified if high rates of intergenerational social mobility cause large proportions of offspring to belong to different social groups from their parents'. The few studies of the interdependence of social mobility, differential fertility, and assortative mating that have been carried out indicate that intergenerational social mobility rates in Western industrial societies are high enough to offset almost all of the potential effects of differential fertility and assortative mating on differential rates of population growth.

See also: Caste; Dumont, Arsène; Intergenerational Transfers; Partner Choice; Social Institutions; Social Reproduction.

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Robert D. Mare