Cities, Demographic History of

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CITIES, DEMOGRAPHIC HISTORY OF

Before the twentieth century, the populations of urban places, and especially the great cities, faced at least one important problem: how to replace themselves. Conventional wisdom has it that ancient, medieval, early-modern, and early-industrial cities were incapable of growing naturally, that mortality was normally in excess of fertility, and that a net balance of in-migrants was necessary to keep the population at even a stationary level, let alone allow its numbers to grow. This has been called the "urban graveyard effect." Eighteenth-century English economist T. R. Malthus, in the second edition of his Essay on the Principle of Population (1803) provides the following description:

There certainly seems to be something in great towns, and even in moderate towns, peculiarly unfavourable to the early stages of life: and the part of the community upon which the mortality principally falls, seems to indicate that it arises more from the closeness and foulness of the air, which may be supposed to be unfavourable to the tender lungs of children, and the greater from the superior degree of luxury and debauchery usually and justly attributed to towns. (Malthus, pp. 256–257)

And,

To fill up the void occasioned by the mortality in towns, and to answer all further demands for population, it is evident that a constant supply of recruits from the country is necessary; and the supply in fact always flowing in from the redundant births of the country. Even in those towns where the births exceeded the deaths, this effect is produced by the marriages of persons not born in the place. (Malthus, p. 257)

These brief passages also reflect a vocabulary about cities and the countryside that was commonly used. While towns display "luxury" and "debauchery," there are "redundant births" in the country ready and willing to fill up the urban void. And in towns, those who suffer most from excess mortality are the children with their "tender lungs." And how else can urban growth be supported but by the offspring of those not born in the towns, that is, the children of migrants?

Such observations required an empirical foundation. Among European populations, it became possible to examine the balance of births and deaths in some detail only after an effective system of parish registers had been established. In England, this means after 1538, and in France, after 1685. Parish registers provide demographers with the number of baptisms, burials, and marriages that can be used to approximate the numbers of births and deaths, and to estimate the general size of the population responsible for those vital events. From such data it is possible to judge the potential for natural population growth in urban compared with rural parishes and thereby to establish the extent to which there is likely to have been excess mortality in the towns.

Many studies exist on seventeenth-, eighteenth-, and nineteenth-century European towns (including those in the Americas, southern Africa, and Australia and New Zealand) based on parish registers, or complemented by Bills of Mortality, which illustrate Malthus's observations. Broadly speaking, urban mortality was higher and fertility lower than in rural areas. In the centuries before the introduction of such registration, however, it is very difficult to discern demographic trends in any detail and it is particularly difficult to identify differences between urban and rural places. In medieval and ancient cities, the assumption that mortality was very high was based on literary references to plagues, invasions, and natural disasters, but it has proved difficult to quantify these events, just as it has been difficult to assess the population sizes of towns in this period. However, there is ample evidence, for fifteenth-and sixteenth-century Italy, to show that its towns were severely affected by outbreaks of bubonic plague; they were far more vulnerable to repeated and severe demographic crises than the countryside. This is true of early modern towns in general.

The development of family reconstitution, a form of nominal record linkage, in the 1950s and 1960s revolutionized historical demographic studies. Estimates of age-specific mortality and fertility rates from parish register data became possible and a far more detailed picture was drawn, especially of the demography of rural parishes. Family reconstitution techniques work to greatest advantage where there is low population turnover so that individuals named in baptism, marriage, and burial registers may be linked within the same parish. If migration is at a high level, individuals will disappear since they may move among parishes between vital events. In these circumstances, the ideal outcome is that baptism and burial registers can be linked to establish estimates of early childhood mortality, especially infant mortality rates.

Researchers' current understanding of urban historical demography rests, therefore, on the following: a long-standing assumption regarding the existence of an urban graveyard effect; many examples of negative natural growth in individual early modern and late medieval towns; and detailed evidence of excess early childhood mortality in urban places.

There are also several points of continuing disagreement. In 1978 historian Allan Sharlin challenged the view that early modern cities were bound to have had natural population decline, and instead focused attention on migration. He argued that while the permanent residents of a city may have been capable of replacing themselves, thereby generating natural growth, the temporary migrants attracted to the city as unmarried workers were likely to add substantially to the number of prematurely deceased, since they confronted, for the first time, the high-risk urban disease environment. In this model, the natural decrease of populations in early modern towns is associated with the mortality of migrants rather than that of the city-born. Many urban historians believe the model overstates the reality, although they accept that attempts to test Sharlin's hypothesis have added considerably to an appreciation of the role of migrants and their potentially distinct demography. The debate on the hypothesis has also encouraged some demographers to challenge the graveyard assumption. They ask:

Were the largest cities at all times subject to natural decline and dependent for their growth on in-migrants from the countryside?;
At what level in the urban hierarchy were the effects of size or population density so substantial that natural decline was likely to be experienced? (In other words, did small towns often escape this problem?);
What particular diseases were involved and which sections of the population were most affected?; and
What was the role of marriage, new household formation, and fertility among migrants and permanent residents?

None of the questions raised are easy to answer. Studies of eighteenth-century London and Paris demonstrate clearly that both cities had birth deficits: They depended on rural migrants to sustain themselves and to grow. In Paris, population increased from 510,000 to 581,000 in the century between 1700 and 1800, and in London, from 575,000 to 865,000 during the same period. But for a town like York (with a population of 12,000 in 1600), there is evidence, for a period in the second half of the sixteenth century during which slow natural growth did occur, that the total number of baptisms exceeded that of burials. This effect may have been repeated in other smaller towns. It is not possible to describe accurately the demographic characteristics of places at different levels in the urban hierarchy until the nineteenth century when many states developed their own civil systems of vital registration. For Victorian England and Wales, there was, in general, an inverse association between life expectancy at birth and both population size and density of the town in which a person lived. Life expectancy was from five to ten years lower in the large towns than in the small towns, and the latter had life expectancies, in turn, a further five to ten years lower than the rural districts. There was a clear urban-rural mortality gradient.

The nineteenth century was also the period in which efforts were first made to record cause of death in a systematic fashion, data which show the effect of water-and air-borne infectious diseases, especially in creating excess early childhood mortality in urban places. For example, measles was an epidemic disease with a particular sensitivity to variations in population density. Children aged from six months up to ten years that lived in towns were especially vulnerable. Measles alone would have made a considerable contribution to the urban-rural mortality gradient, but its effect was accentuated by scarlet fever and whooping cough among children, and diarrhea among infants. Similar patterns may have existed in earlier centuries when smallpox, for example, would have added to the childhood mortality rate.

Apart from the methodological revolutions brought about by family reconstitution and computer-based analysis of large and complex data sets, urban historical demography has also been influenced by the shift in research emphasis away from work on demographic crises and mortality toward nuptuality and fertility. Age at marriage, proportions marrying and re-marrying, marital and non-marital fertility, and the practices of breastfeeding or using wet nurses are factors drawn on in explaining long-term changes in the population growth rates of cities, as well as differences among urban environments.

Cities as Parasites or Growth Engines?

Economic historians have long debated whether cities should be regarded as parasites or engines of economic growth. This debate reflects a sense of ambivalence in Western culture toward the city. While the city states of ancient Greece and Rome, and renaissance Italy, represented the pinnacle of civilization–indeed they were its defining expressions–the merchant and industrial cities of more recent centuries generated strong and mixed emotions. Malthus regarded Georgian London as rich yet debauched, while to lexicographer and author Samuel Johnson (1709–1784) it exemplified the very vitality of life. Demographers have also expressed mixed feelings. In 1987 economic historian E. A. Wrigley, for example, depicted seventeenth and eighteenth century London as a "death trap," but he also demonstrated its importance for economic and social change in preindustrial England. London absorbed England's surplus rural population; it acted as a single, integrated market for food products and consumer goods as well as finance; it stimulated agricultural production especially in its region; and it set the social fashions and was the center of political power. Until the rise of the industrial cities of the English midlands, London had no rivals, and even afterward the competition was relatively short lived. Florence in the fifteenth century, on the other hand, has been likened to a shining sun in a countryside drained of wealth and enterprise.

Urbanization

Urbanization depends on the ability of the urban population of a country or region to grow at a faster rate than its non-urban population. Usually this implies that the urban sector is experiencing natural growth and net in-migration from the rural sector, although it may also involve reclassification of places from rural to urban as they acquire larger populations or non-agricultural functions. In principle, it is possible for urbanization to progress while the graveyard effect persists, but rapid urbanization requires rapid urban growth and that demands both net transfers from the rural to the urban population and the capacity of city dwellers to more than replace themselves. In the past, rates of urbanization have been slow, although with considerable variations between regions. Western Europe was perhaps 8 to 10 percent urban by 1800 and 30 to 35 percent urban by 1900, whereas China only reached 36 percent urbanization in 2000. These varying historical levels of urbanization are difficult to interpret. Apart from the problem of different definitions of "urban," they probably reflect both variations in the progress of economic development and culturally based attitudes to the urban way of life: tolerated in Europe, restricted in China.