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。     

Contraceptive Initiation Patterns in Thailand

Data from the Thailand Demographic and Health Survey permit a detailed examination of the pattern of contraceptive initiation in terms both of first post-marital contraceptive use and initiation of use following childbirth. A clear trend towards beginning contraception earlier in the family-building process over the course of the fertility transition is evident. During the earliest stage, contraception was first used mainly after a couple had already achieved their desired family size, but later on couples increasingly began use in order to space births, and most recently it has become common to begin use to delay the start of childbearing. There are two distinctive patterns of contraceptive initiation following childbirth. For women who chose sterilization, initiation occurs during the immediate post partum period, while for those who used other methods, use most commonly began shortly after the return of menses. As a result, few Thai women are at present unprotected against unplanned pregnancies for any substantial period of risk following childbirth. Beginning to use contraception early in the family-building process and rapid adoption of contraception following childbirth are now found in most segments of Thai society, testifying to the maturing of Tailand's fertility transition.     

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.     

Personal Wellbeing Index in a National Cohort of 87,134 Thai Adults

Satisfaction with life correlates with other measures of subjective wellbeing and correlates predictably with individual characteristics and overall health. Social indicators and subjective wellbeing measures are necessary to evaluate a society and can be used to produce national indicators of happiness. This study therefore aims to help close the gap in wellbeing data for Thailand. The specific aims are to: (1) calculate the Thai PWI and domain scores using a large scale sample; (2) examine the level of life satisfaction of Thais when compared to international standards; (3) examine the Thai PWI and domains in relation to demographic, socioeconomic, and geographic characteristics. Our report derives from the findings on the Personal Wellbeing Index (PWI) in a large national cohort of Sukhothai Thammathirat Open University adult students living all over Thailand (n = 87,134). This Thai cohort had an overall PWI of 70.0 on a scale from 0 to 100 which is consistent with Western populations. The ‘spirituality and religion’ domain had the highest average score. ‘Standard of living’, ‘future security’ and ‘achievement in life’ made the largest contribution to overall ‘satisfaction in life as a whole’. These domains also show a positive trend with increasing age, being married, higher income, more education, more household assets, and rural residence. The PWI will be an important tool for policymakers to understand the subjective wellbeing of population groups especially as Thailand is undergoing a political and economic transition.     

Population statistics] as of July 1, 1998

This article presents estimates of relevant population numbers and vital rates in Thailand as of July 1, 1998. Utilizing the standard demographic techniques of analysis, the estimates provided are assured to be the most accurate demographic estimates possible. Total population was estimated at 61,143,000. Estimates by sex, locales, region, and by age group are included. In addition, the crude birth rate per 1000 population was estimated at 18.7; the crude death rate per 1000 population was 6.5. For the natural growth rate the estimate was at 1.2%, and the infant mortality rate was 25.0 per 1000 live births. In terms of life expectancy at birth, the estimate for males was 69.9 years, while for females it was 74.9 years. Additional years in life expectancy at age 60 were 20.3 years for males and 23.9 years for females. The total fertility rate per woman is 1.98, and contraceptive prevalence is 72.2%. The demographic data will be disseminated to Thai and international population researchers and planners.     

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.     

Below-replacement fertility in Thailand and its policy implications

The fertility transition in Thailand has been one of the most rapid among Asian countries that are yet to attain newly industrialized country status. In the early 1960s, the total fertility rate exceeded six births per woman; currently, it stands at 1.9 or slightly below replacement level. At present, it is hard to predict the future trend in fertility as this involves several factors that need much closer study, in particular, fertility preferences, changes in marriage patterns and the wider effects of the current economic crisis in Thailand. Rapid declines in fertility and mortality have had a profound effect on the age structure of the population, notably the increasing elderly proportion. Thailand now faces new challenges and priorities for population policy. Policy responses to concerns arising from below-replacement fertility will be much more complex and involve greater government activism, improved institutional capacities and more resources than in the past. This paper reviews the fertility transition in Thailand and looks at some consequences and policy implications of low fertility, with special reference to the family and the elderly population. National Statistical Office     

The Momentum of Real Population Under Linear Fertility Transition

Population momentum is the ratio of a population's ultimate size after a demographic transition to its initial size before the transition. For stable population and instantaneous drop to replacement fertility, Keyfitz found a simple formula for the momentum. Although Keyfitz's formula has been extended to cover gradual demographic transitions, the stable initial population, however, is still an obstacle to approaching reality. Using the solution of the Lotka equation with time-varying vital rates and extending it to negative values of time, exact and accurate formulae for the momentum of any initial population that undergoes a linear fertility transition are expressed. Examples using the data from the United Nations indicate that the accurate formula works well for the age structures that are far from stable such as the more and less developed regions, as well as that close to stable such as the least developed region.     

Population momentum for gradual demographic transitions

Population momentum is the ratio of a population's ultimate size after a demographic transition to its initial size before the transition. For an instantaneous drop to replacement fertility, Nathan Keyfitz found a simple expression M K for the momentum. However, as Keyfitz pointed out, `no one thinks that any country will drop immediately to stationary reproduction patterns'. We present results concerning the momentum of a population whose demographic transition is completed within a finite time. First, we provide an exact analytical formula for such a population's momentum. Second, for rapid fertility transitions, we obtain a simple exact expression for momentum that reduces to Keyfitz's M K if the transition is instantaneous. We show, by example, that our simpler formulae are accurate approximations to population momentum for transitions that take as long as 100 years. Finally, we show that the speed of fertility decline makes a substantial difference to population momentum.     

On the scale of global demographic convergence, 1950-2000

The second half of the twentieth century saw global demographic change of unprecedented magnitude, with pronounced falls in both mortality and fertility in many developing countries. This article assesses the extent to which these changes have led to the convergence of demographic patterns around the world. It considers not just the levels of fertility and mortality in each country at different points in time, but also the size of each population. It also disaggregates China and India into their constituent provinces and states in order to provide estimates for units more typical of the size of the populations of other countries. The note presents proportions of the world's population according to the levels of life expectancy and total fertility they experienced in the early 1950s, the late 1970s, and around 2000. The graphs and tables thus produced give a convenient and novel way to view the scale and nature of demographic convergence over the last 50 years.     

Demographic aspects of fertility in Thailand

Abstract Data from a national rural and urban sample survey are analysed in order to examine various demographic aspects of fertility in Thailand. Marital fertility rates found for Thailand are among the highest in Asia. Particularly noteworthy is the persistence of high fertility at older ages of childbearing for rural women. Cumulative fertility shows a pronounced relationship with age at marriage and current marital status. Women who marry at an older age or who experience disruption of their marriages are clearly more likely to have fewer children ever born. Differences in both current and cumulative fertility are strongly associated with residence. Rural women who constitute the vast majority of Thai women, experience the highest fertility, Bangkok-Thonburi women experience the lowest fertility and provincial urban women are characterized by an intermediate fertility level which is closer, however, to the experience of their counterparts in the capital than in the countryside. Rural-urban fertility differences are mitigated but by no means eliminated by differences in infant mortality. In both rural and urban areas a positive association between cumulative fertility and infant morality is evident. Breast-feeding, commonly practised for extended periods-among both rural and urban Thai women, undoubtedly serves to some extent as an intervening variable in this relationship. A comparison of current fertility with cumulative fertility strongly suggests that a decline in marital fertility has been under way recently among urban women, especially those residing in the capital, but not at all among rural women. Although it seems safe to assume that the urban fertility decline results in large part from an increasing use of contraception among urban women, those still in the reproductive ages who were using or had previously used birth control were characterized by higher cumulative fertility than women who had never practised contraception. Evidently couples resort to family planning only late in the family building process after they have already achieved or exceeded the number of children they wish to have.     

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.     

Population momentum for gradual demographic transitions: an alternative approach

In this article, I derive a simple formula for approximating the ultimate size of a population that undergoes a gradual transition to replacement fertility. I model the fertility transition by specifying a linear frontier on the Lexis surface across which a change in fertility is instantaneous. Gradual transitions result from variations in the slope of this frontier. This framework can be used to reproduce and understand previous studies of population momentum and gradual transitions.     

Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers

Forest conversion for agriculture expansion is the most salient signature of human occupation of the earth's land surface. Although population growth and deforestation are significantly associated at the global and regional scales, evidence for population links to deforestation at micro-scales—where people are actually clearing forests—is scant. Much of the planet's forest elimination is proceeding along tropical agricultural frontiers. This article examines the evolution of thought on population–environment theories relevant to deforestation in tropical agricultural frontiers. Four primary ways by which population dynamics interact with frontier forest conversion are examined: population density, fertility, and household demographic composition, and in-migration.     

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.     

A rejoinder to S. K. Datta and J. B. Nugent

Extract

The question of old-age security as a motivation for fertility in less-developed rural areas can be put in clearer perspective by pausing to consider the changing roles of land and offspring under the influence of fundamental demographic upheaval. Under the pre-transition regime, one generation approximately replaced the preceding one, particularly once unused but usable land became scarce and the possibility of expanding farm operations became remote. Judging from the settlement patterns and the history of the Maharashtrian study area, such a circumstance probably obtained long before the secular drop in mortality began. During this period, a single son, typically, would survive to adulthood, gradually assuming control of the father's land (or the father's trade, among non-agriculturalists) and, if the father lived long enough, would eventually be a source of security in the father's old age. It is not inappropriate to mention that this generational cycle no doubt fostered a strong urge to leave the family land to a son, so that a sonless farmer would keenly feel a lack of fulfilment. In fact, responses to certain survey questions suggest that ancestral land and male progeny are still somehow connected, according to the way village men think, to their sense of immortality. It would be hard, consequently, to separate old-age security, the idea of ‘continuing a lineage’, and the sense of immortality conferred by owning land into distinct motives for conceiving children.     

Policy options when population growth slows: The case of Thailand

Thailand reached replacement-level fertility almost a decade ago, although there has been a lag in measuring and recognising the implications of this benchmark event. Fertility could well sink still lower. The momentum of population growth will ensure substantial further increase before the population levels off, but this is not true in all regions. For example, earlier and faster fertility decline in the North, and net outmigration, have led to a situation where some geographical and age segments of the North's population are decreasing. Population policy in Thailand since 1970 has had two major planks: to reduce fertility through an active family planning program, and to distribute population away from the large primate city of Bangkok. The paper discusses whether these policies may need to be modified as a result of the major demographic and socio economic changes that have been taking place. It also discusses the limits to population policy in terms of the likely efficacy of various measures that could be adopted, based on both an assessment of the Thailand situation and the experience of other low-fertility countries.     

Women's lives and rapid fertility decline: Some lessons from Bangladesh and Egypt

The recent experiences of Bangladesh and Egypt show thatfertility can sustain impressive declines even when women's lives remain severely constrained.Since the late 1970s, rural and urban areas in both countries have experienced steadydeclines in fertility, with recent declines in rural Bangladesh similar to those in ruralEgypt, despite lower levels of development and higher rates of poverty. This paperprovides an in-depth exploration of the demographic transition in these two societies andaddresses three basic questions: (1) have measurable improvements in economic opportunities forwomen been a factor in the fertility decline?; (2) can preexisting differences in gender systemsexplain the more rapid fertility decline in Bangladesh, despite the more modest economicachievements?; (3) can the development strategies adopted by the governments ofBangladesh and Egypt, be seen as additional factors in explaining the similar rural fertilitydeclines despite dissimilar economic circumstances? The paper concludes that neither gender systemsnor changes in women's opportunities appear to have contributed to declining fertility.Indeed, low levels of women's autonomy have posed no barrier to fertility decline in eithercountry. However, there is a case to be made that Bangladesh's distinct approach to development,with considerable emphasis on reaching the rural poor and women and a strong reliance onnongovernmental institutions, may have played a part in accelerating the transition in thatenvironment and in helping women to become more immediate beneficiaries of that process.

     

Factors affecting fertility of natives and migrants in urban Brazil

Abstract Modernization is expected to change the patterns of population growth of developing countries. The primary reason explaining the fast rate of population growth of these nations has been established as that of the reductions of mortality! which marks the first stage of demographic transition. The second stage in this process is the reduction in fertility which counterbalances lowered mortality and therefore reduces the rate of population growth. This latter phase has been achieved in modern industrial societies.