Demographic Theory: A Long View

This essay argues that demographic theory over the last half‐century has substituted short‐term explanations, often focusing on single demographic events, for long‐term theory. This means not only that the explanations cannot be employed to forecast the situation in the more distant future, but they are inadequate even for short‐term analysis. A basis for a longer‐term theory of fertility transition is proposed, employing the concept of social structure and demographic behavior adjusting, slowly and after a considerable lag, to each of three modes of production. The focus is on the transition from agricultural to industrial production, especially as this is occurring in the most advanced industrial societies. Three major conclusions are drawn. (1) Unanticipated fertility changes over the last 50 years can be incorporated within a single demographic transition theory. (2) Societal and demographic changes are still at an early stage of their transition to full adjustment to industrialization. (3) The trend, associated with women's participation in the work force, toward below‐replacement fertility will continue, but at some stage most governments will probably attempt to raise fertility to replacement level even if the effort is extremely expensive and slows economic growth.     

Mortality–fertility synergies during the demographic transition in the developed world

The classic theory used to explain the demographic transition assumes that mortality is the key explanatory variable influencing the decline in fertility. However, the empirical results obtained in what is known as the Princeton European Fertility Project have led many specialists to question this assumption. Using both national and provincial aggregated data for 25 countries over a long time span, the analysis reported in this paper found that mortality does indeed play a fundamental role in accounting for the main demographic changes that occurred both before and during the transitional period. Others’ research based on individual data has shown clearly that the number of surviving children was indeed an important factor for reproductive decisions. My analysis, using aggregated data, reached largely similar conclusions regarding the role of mortality in changing reproductive trends, via its impact on nuptiality and marital fertility at different stages of the demographic transition.     

Fertility decline in the modern world and in the original demographic transition: Testing three theories with cross-national data

This study uses aggregate data on a large number of the world's societies to test three theories of fertility decline in the modern world and in the original demographic transition. One prominent theory relates fertility decline to the changing economic value of children. With industrialization and overall modernization the economic value of children's labor shifts from positive to negative. This interpretation has been challenged by those who claim that the flow of wealth in preindustrial societies is always from parent to child rather than from child to parent. An alternative interpretation is that fertility levels reflect people's efforts to promote their reproductive success, and that this requires the careful tracking of infant and child mortality. Fertility rates are adjusted to the rate of infant and child survival, and will be high when survival rates are low and low when survival rates are high. A third theory emphasizes female empowerment. Fertility will be high when women are highly subordinated to men, but as women gain more autonomy and control over their own lives they reduce their fertility levels because, among other possibilities, higher levels of fertility present them with serious burdens. We tested all three theories through multiple regression analyses performed on two samples of societies, the first a large sample of the world's nation-states during the period between 1960 and 1990, and the second a sample of now-developed societies between 1880 and 1940. Our findings showed that infant mortality was an excellent predictor of fertility, and that female empowerment was a good predictor. However, there was only weak support for the argument that the economic value of children's labor plays an important role in fertility decisions. The findings were discussed in the context of a broader interpretation of fertility behavior in societies with high levels of industrialization and modernization.     

Effects of Childhood Mortality and Morbidity on the Fertility Transition in sub‐Saharan Africa

Child mortality rates have fallen substantially in developing countries since 1960. The expected fertility decline has followed only weakly in sub‐Saharan Africa compared to other recent and historic demographic transitions. Disease and anthropometric data suggest that morbidity remains prevalent in Africa despite child survival improvements. The uniquely high infectious disease burden among children in Africa reduces population health and diminishes the returns to human capital investment, thwarting the quantity–quality tradeoff for children that typically accompanies the mortality transition. Individual‐level data from the Demographic and Health Surveys are used to show that persistent morbidity has weakened the positive relationship between child mortality and total fertility rates throughout the region, slowing Africa's demographic transition.     

人口老龄化机制研究:基于生育率持续下降视角

人口老龄化现象主要通过人口转变理论解释,由于生育率下降不满足经典的人口转变理论设想,人口转变理论对人口老龄化的解释力受到挑战。从制度的角度研究社会养老制度建立以后形成的"社会养老、家庭养子"对生育率的影响,以期解释人口转变结束后生育率持续下降的原因,从生育率下降视角研究人口老龄化机制。研究发现,在"社会养老、家庭养子"制度下,养子收益减少、养子成本提高、家庭养子资源比例减少,使家庭生育率下降,生育率下降导致人口老龄化程度加深;人口老龄化程度加深提高养子成本、降低家庭养子资源比例,由于家庭缺乏养子激励,生育率进一步下降,进而导致更严重的老龄化。老龄化一旦形成,具有不断强化的机制。     

Understanding Global Demographic Convergence since 1950

Is the world converging to a single demographic regime? Or are groups of countries following distinct paths through the process of demographic transition? The answers to these questions are pivotal to our understanding of the nature and mechanisms of population change. They are also key elements for deriving the assumptions that should underlie population projections. There has been considerable interest in global demographic convergence during the last decade, with most work drawing on statistical methods that are widely used in economics. This article takes a different approach to most of the existing literature, examining the fertility and mortality trajectories over time that various appropriately defned world regions have followed. The data suggest that five distinct regional histories can be traced in mortality, and three in fertility, and that global convergence has moved more rapidly and unambiguously in fertility than in mortality.     

Epidemiologic transition in the United States: the health factor in population change

The general theory of epidemiologic transition is explained. The theory hypothesizes that long-term changes in health and disease patterns in any society are related to the demographic and social conditions in that country. Mortality is considered to be the major factor in population change. The theory is illustrated by a detailed consideration of birth and death trends in the U.S. Mortality decline began in the U.S. in the middle of the nineteenth century. Associated with this decline was a gradual shift from death due to infectious disease to mortality caused by degenerative, man-made, and stress-related diseases. The transition favored women, children, and whites. Medical progress was less responsible for the change than were improvement in living conditions and changes in the nature of certain diseases. The magnitude of this decline in mortality is illustrated by an analysis of 5 specific indicators of mortality. Changes in the U.S. fertility patterns were also unplanned and attributable to socioeconomic factors rather than to medical advances. Comparison of the transition in the U.S. with the same movement in England shows that the U.S. experience fits the Western or Clasical Model of the epidemiologic transition theory. This experience cannot be used as a model for the transition occurring now in the Third World. In those countries, programs organized in the context of general social development projects could be expected to influence trends in mortality and fertility.     

The new point in population theory: some questions in the current demographic textbooks]

The current population theory in China emphasize that human reproduction must keep pace with the production of goods and services. The author of this paper challenges this theory and believes that the relationship between these two kinds of production, human reproduction should take the principal place. Production of goods and services must first meet the needs of people. Keeping population growth in pace with production of goods and services is of secondary importance. The demographic transition from high fertility and high mortality to low fertility and low mortality in developed country was not caused by poverty, hunger, and surplus of the labor force, and it was not the end result of forcing population growth to stay in pace with material production. Increasing productivity to provide abundant goods depend on improving the quality of the population. When the purpose of consumption is not only for survival, demands for material goods and leisure will take precedence over demands for children. An-emphasis on keeping population reproduction in pace with the production of goods and services tends to ignore the importance of increasing productivity which is the key to the improvement of living standards.     

Crossovers that link populations with the same vital rates

"In this paper, we consider crossovers of demographic density distributions from...populations that have the same fertility and mortality rates. We focus on observed populations and their associated stationary and stable models, and on proportional distributions of persons, births, deaths and reproductive values....Three different populations were selected to represent a range of demographic behavior. Those populations are Japan 1963, a low mortality, low fertility population; Togo 1961, a high mortality, high fertility population; and the United States 1919-1921, a population whose fertility and mortality are intermediate."     

Malthusian models and Chinese realities: the Chinese demographic system, 1700-2000

This article summarizes major recent findings on Chinese demographic behavior and outlines their relevancy for the Malthusian model of comparative population dynamics and Chinese population in particular. Specifically, it considers four distinctive and persistent features of Chinese behavior during the last 300 years—high rates of female infanticide and abortion, high rates of bachelorhood, low marital fertility, and high rates of male and female adoption–and discusses the origins and implications of such a demographic regime for Chinese economic and social development. Contrasting Chinese demographic behavior with European demographic behavior, the article argues the existence of a demographic system and a demographic transition different from current Malthusian and neo-Malthusian models, and the existence of a system regulating collective demographic behavior in ways distinctly different from Western experience.     

中国特色的人口转变

从人口均衡发展的角度对人口转变理论进行了研究,认为人口转变是由低级人口均衡转变为高级人口均衡的跃迁过程,人口"总量相对静止、结构高位稳定"是最理想的人口发展状态。中国人口转变经历了超前经济发展的"人口转变"和与经济互动发展的"后人口转变"两个阶段,人口转变过程中需跨越"高少儿抚养"和"高老年赡养"的两次陷阱。稳定适度低生育水平和提升人口素质是未来根本任务,从较短期看总和生育率保持在1.8左右,从中长期看总和生育率回归更替水平,是"后人口转变"时期的战略目标,也是促进人口长期均衡发展的必由之路。     

Effects of child mortality on subsequent fertility of women in some rural and semi-urban areas of certain Latin American countries

Abstract With the rapid decline in child mortality in developing countries there is considerable interest in understanding its effects on fertility. According to the theory of demographic transition, mortality declines are accompanied by fertility declines after a time lag, as countries go through the process of economic development. However, the immediate effects of a mortality decline on fertility have not been uniform as in many countries fertility has actually increased. For example, in many Latin American countries where mortality declines have been very rapid there have not been any appreciable changes in fertility. Only in recent years has there been a noticeable decline in the urban areas of some nations. While it is possible to examine the effects of various socio-economic factors on mortality and fertility at the macro-level, any real understanding of how mortality itself influences fertility would require information at the micro-level on couples who have experienced child mortality and who are also exposed to the risk of childbearing.     

中国人口的迁移转变——基于迁移率的考察

经典人口转变理论侧重死亡和生育转变过程的测量、描述和解释,地理学家将迁移转变纳入人口转变框架,以完善人口转变理论。不过与死亡和生育转变研究不同,中国的迁移研究侧重基于对迁移流动人口规模和结构的考察分析,少有采用人口学意义上的迁移率指标的研究。文章利用2010—2015年历次中国综合社会调查的合并数据,通过人口学方法和泊松回归模型,计算和分析了1950—2015年中国人口迁移率趋势及社会经济差异。中国的迁移转变在宏观趋势上与中国的政治经济变迁高度一致。与死亡和生育转变相比,其波折性更强,说明更易受到经济社会政策变化的冲击。同时也观察到逢“0”和逢“5”年份的申报偏好。另外,迁移的社会经济差异明显。男性迁移率高于女性,但是两性差异在不断缩小;乡城迁移和未婚迁移大幅度增长;而越来越多受教育程度较高人群加入迁移,使得受教育程度越高的人群具有越高的迁移率。可以认为基于迁移率的考察揭示了中国迁移转变更具体生动的过程。     

Child mortality and fertility: public vs private education

How does the effect of child mortality reductions on fertility and education vary across educational systems? To answer this question, we develop an overlapping-generations model where altruistic parents care about both the number and human capital of their surviving children. We find that, under a private education system, if income is low initially, the economy converges to a Malthusian stagnation steady state. For a high level of initial income, the economy reaches a growth path in which children’s education rises and fertility decreases with income. In the growth regime under private education, exogenous shocks that lower child mortality are detrimental for growth: fertility increases and education declines. In contrast, under a public education system, the stagnation steady state does not exist, and health improvement shocks are no longer detrimental for growth. We therefore offer a new rationale for the introduction of public education.     

Poverty,Inequality, and Fertility: The Contribution of Demographic Change to Global Poverty Reduction

Global poverty has fallen dramatically over the past decades. In many developing countries, this transformation was accompanied by rapid improvements in demographic outcomes, such as falling child mortality and fertility. Yet, recent theorizing and empirical research into the causes of global poverty reduction has mostly omitted demographic factors. This paper aims to fill this gap by testing for effects of demographic variables on poverty. Using time series data for 140 countries, we document a strong effect of lagged fertility on country-specific poverty rates. This effect is robust across several specifications and data sets. It appears to be stronger in countries with larger fertility differentials, in the early transition stages. The proposed mechanism behind this result is a “Kuznets curve-type” expansion of fertility inequality at the onset of the demographic transition. We conclude by calling for a stronger inclusion of demographic variables in the distribution-sensitive analysis of global poverty.     

Bridewealth and Birth Control: Low Fertility in the Indonesian Archipelago, 1500–1900

Before the onset of the present demographic transition, population growth in Indonesia had reached unprecedentedly high levels. This article demonstrates that such high levels were a recent phenomenon. Prior to 1900 rates of natural population increase were low to very low in most areas in Indonesia. This runs counter to expectations based on Hajnal's “Eastern marriage pattern,” which could imply high growth levels in extended family areas, such as most Indonesian regions outside Java in the past. Usually, the low population growth rates in Southeast Asia are attributed to high mortality owing to high levels of violent conflict. It is argued that other factors contributing to such high levels of mortality should receive more attention. In this article it is also argued that low fertility rates, too, played a role in generating low rates of natural increase. The article discusses the influence of marriage patterns, household structure, methods of birth control, adoption, and slavery on fertility.     

The phoenix population: Demographic crisis and rebound in Cambodia

The study of mortality crises provides an unusual and valuable perspective on the relationship between mortality and fertility changes, a relationship that has puzzled demographers for decades. In this article, we combine nationally representative survey and demographic-surveillance system data to study fertility trends around the time of the Khmer Rouge (KR) regime, under which 25% of the Cambodian population died. We present the first quantitative evidence to date that attests to a one-third decline of fertility during this regime, followed by a substantial "baby boom" after the fall of the KR. Further analyses reveal that the fertility rebound was produced not only by a two-year marriage bubble but also by a surge in marital fertility that remained for nearly a decade above its precrisis level. Our results illustrate the potential influence of mortality on fertility, which may be more difficult to identify for more gradual mortality declines. To the extent that until recently, Cambodian fertility appears to fit natural fertility patterns, our findings also reinforce recent qualifications about the meaning of this core paradigm of demographic analysis.     

中国的家庭结构转变--来自居住方式与人口因素的作用

基于历次人口普查数据,利用SOCSIM微观模拟方法将家庭转变的关键影响因素分解为人口因素和居住方式因素两个方面,并进一步将人口因素分解为人口惯性、生育率、死亡率和结婚率四个层面进行计量分析.结果发现,当前人口变动相对稳定,较小的波动使其在家庭转变中的贡献率相对较小,而居住方式的影响相对较大;对人口因素的进一步分解还发现,人口惯性及生育率水平的作用相对更大,生育率水平、结婚率水平带来的影响与人口因素的总影响方向是一致的,均提高了一人户、一代户、二代户的人口比重,降低了三代及以上户的人口比重.与之相反,死亡率的影响与人口因素的总影响方向是相反的.     

The End of the Demographic Transition: Relief or Concern?

Demographic transition theory might seem to imply that, after a period of exceptional population growth resulting from the time lag between mortality and fertility declines, every population, and then the whole world population will stabilize and, consequently, no more acute population problems will appear. Does the claim, recently gaining credibility, that the end of the transition is at hand actually imply a stage without major population problems? Nothing is less sure. First, it is just a claim, the realization of which still entails a period of dramatically rapid population growth in some countries, especially the poorest. But more tellingly, the end of the transition is also the end of the paradigm on which we have been relying to understand and anticipate demographic changes. Nobody knows what might ensue later: How long and low can fertility fall? How long and high can life expectancy increase? How far can population aging go? As many questions without answer and probably as many problems whose size we cannot even imagine lie ahead.     

On Net Intergenerational Wealth Flows: An Update

Almost 30 years have passed since I introduced the concept of “net intergenerational wealth flows” in a PDR essay, “Toward a restatement of demographic transition theory.” A great deal of research has been published since then, and accordingly an update is needed. That research suggests the following propositions. Immediately before fertility transition, children's farm labor may not quite offset their consumption, although much depends on how far into adulthood they continue to perform at least some work for their parents. In premodern times children may have paid their way because of lower consumption. Research on the pre‐transitional value of children's work produced contradictory results because it examined both hunter‐gatherer societies, in which both adults and children worked comparatively few hours, and farming societies, in which both worked longer hours. In pre‐transitional societies, the insurance value of children was almost unlimited. For most people in most societies, alternative ways of maintaining savings from the earlier to the later stage of the life cycle first became available only when large‐scale investment in children's education was possible. The costs and gains from that investment played a major role in the onset of the fertility transition.