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.     

A review of the studies on fertility transition in China]

This article is a summary of papers and analysis in recent years on fertility transition and the association between fertility decline and socioeconomic development in China. These papers discuss the causes of fertility decline and the role of family planning programs in demographic transition. The major points are: 1. The demographic transition in China has the same characteristics as in the countries that have completed the transition. The transition had already started in the more developed areas or completed in a few large cities before family planning programs were implemented. 2. The role of family planning programs is to lead and to accelerate the demographic transition, which is the key idea of the "induced fertility transition". 3. The socioeconomic development and family planning programs worked together to affect the fertility decline, however socioeconomic development is the fundamental factor. Without the existence of the socioeconomic development, which included the changes in the function of family, traditional ideas on fertility, increased level of education, the status of women and social security system; the family planning program is not likely to make an impact.     

The pattern of birth spacing during Taiwan's demographic transition

This paper considers the impact of an extended family structure on the fertility behavior of married women in Taiwan. A sequential duration model is applied to identify the differences in fertility behavior during the early and latter stages of a woman's reproductive period. Heterogeneity adjustments which correct the respondent-specific characteristics are also implemented. It is found that living with the husband's parents has an impact on the wife's fertility only at the early stage of her childbearing period, and that the subjective son preferences together with the objective fact of no son in the previous 2 births do force a wife to expedite her third birth. These results are robust across different cohorts during the demographic transition and under different specifications of hazard functions. We thank an anonymous referee for his or her valuable comments and suggestions. Responsible editor: Junsen Zhang.     

Changes in the family status of elderly women in Korea

As a result of sharp declines in fertility and mortality, the aging of the Korean population has proceeded rapidly and is likely to continue in full force for some time. In societies such as Korea, where families traditionally have been the only efficient source of support for the elderly, an aging population poses a threat because families have fewer descendants available to care for increasing numbers of surviving elderly persons. The exact magnitude of the reduction in the supply of kin depends on details of the demographic trends and cannot be evaluated a priori. In this paper we use family-status life tables to assess the effects of changes in demographic processes on the family status of elderly women and to project trends in elderly women's family status.     

Is There a Stabilizing Selection Around Average Fertility in Modern Human Populations?

Possibly the greatest challenge for an evolutionary explanation of demographic transition is the fact that fertility levels universally start to fall first among the well‐to‐do, well‐educated, healthy classes, which can be explained only by some voluntary or at least adaptive action. The problem of how restraints on fertility could have evolved by natural selection has been tackled with group selection models as well as with stabilizing selection models. The latter model, which is critically discussed in this article, posits that some intermediate (rather than maximal) level of fertility is optimal for long‐term reproductive success. Tests of stabilizing selection in human populations are rare, their results inconclusive. Here four sets of data are analyzed: they are samples drawn from the 'class of 1950 of the US Military Academy at West Point (cohorts 1923–29), retired US noncommissioned officers (cohorts 1913–37), and western German and eastern German physicians (cohorts 1930–35), all containing fertility data over two generations, and from European royalty (cohorts 1790–1939) containing fertility data over four generations. Deterministic as well as stochastic fitness measures are used. It is found that maximal, not average, fertility in the first generation leads to maximal long‐term reproductive success. Also against prediction, no decreasing marginal fitness gains by increasing fertility can be observed. The findings leave little space for considering stabilizing selection as a plausible mechanism explaining the course of demographic transition but indicate instead that biological evolution today is as fast and vigorous as ever in human history. Even in large populations, all people living today may be the descendants of just some few percents—a much smaller proportion than generally believed— of the people living some generations ago.     

A fertility analysis of New Zealand marriage cohorts

New Zealand annual returns of non-Maori live legitimate births 1913 to 1955 were tabulated longitudinally by marriage duration and birth order. The figures were used as numerators of fertility rates of forty marriage cohorts, specific for duration and birth order ; the twenty-four oldest cohorts had virtually completed fertility. For the denominators of the rates, the cohorts of initial size (estimated by a method similar to that described by P. H. Karmel) were survived by observing changes over time through divorce, death, widowhood, war-widowhood, and net external migration. The aim was to provide a set of data of the best possible approximation on variations of cohort fertility.

Total cohort rates, cumulated for twenty years’ duration of marriage, and segmental rates of relevant sub-periods are given for parities o to 7+. Total rates of the cohorts of completed fertility yielded values of family size, and were also used for parity progression ratios (by L. Henry’s formula). Segmental rates permitted a study of changes in timing maternities.

The analysis, which needs as a corollary a nuptiality analysis, is concerned, so far with past experience. It confirms the decline in number and proportion of large families. Both the parity progression ratios, and segmental rates of cohorts of as yet incomplete fertility, suggest some recent recovery in three- and fourchild families. For total fertility, such recovery might even be more significant than the observed decline in large families. On the other hand, birth-order specific changes in timing suggest lengthening of intervals among older cohorts as a trend upon which is superimposed the fluctuation due to postponement of, and recovery of a portion of postponed maternities. A construction of hypothetical timing patterns for incomplete cohorts by a simplified method of projection does not lead very far without support of observations on spacing that differentiate for family size.     

How female education affects reproductive behavior in urban Pakistan

Although Pakistan remains in a pretransitional stage (contraceptive prevalence of only 11.9% among married women in 1992), urban women with post-primary levels of education are spearheading the gradual move toward fertility transition. Data collected in the city of Karachi in 1987 were used to determine whether the inverse association between fertility and female education is attributable to child supply variables, demand factors, or fertility regulation costs. Karachi, with its high concentration of women with secondary educations employed in professional occupations, has a contraceptive prevalence rate of 31%. Among women married for less than 20 years, a 10-year increment in education predicts that a woman will average two-fifths of a child less than other women in the previous 5 years. Regression analysis identified 4 significant intervening variables in the education-fertility relationship: marriage duration, net family income, formal sector employment, and age at first marriage. Education appears to affect fertility because it promotes a later age at marriage and thus reduces life-time exposure to the risk of childbearing, induces women to marry men with higher incomes (a phenomenon that either reduces the cost of fertility regulation or the demand for children), leads women to become employed in the formal sector (leading to a reduction in the demand for children), and has other unspecified effects on women's values or opportunities that are captured by their birth cohort. When these intervening variables are held constant, women's attitude toward family planning loses its impact on fertility, as do women's domestic autonomy and their expectations of self-support in old age. These findings lend support to increased investments in female education in urban Pakistan as a means of limiting the childbearing of married women. Although it is not clear if investment in female education would have the same effect in rural Pakistan, such action is important from a human and economic development perspective.     

Levels of Support from Children in Taiwan: Expectations versus Reality, 1965–99

Both population aging and the socioeconomic changes that often accompany it have effects on intergenerational arrangements. As a result, assessing the evolving social contract among family members is a key part of the research agenda. Studies monitoring these effects and other consequences are relatively new. Another way to gain insight is through a historical analysis that (a) traces how expectations for old‐age support have changed over recent decades for cohorts advancing through their life cycle, and (b) measures how well expectations accord with actual patterns. This article uses a series of fertility surveys in Taiwan from 1965 to the 1990s to trace expectations for coresidence among cohorts of young married women and to compare these expectations with the actual living arrangements observed in surveys of the elderly in the 1990s. The results indicate sharp shifts in expectations for each of the cohorts as they aged. These shifts reflect a response to respondents' own life course events and the changing socioeconomic environment and show large and persistent differentials by education throughout the period. These factors tend to bring expectations into fairly close concordance with the actual living arrangements observed some years later.     

Birth spacing and fertility limitation: a behavioral analysis of a nineteenth century frontier population

Our analysis of changing birth interval distributions over the course of a fertility transition from natural to controlled fertility has examined three closely related propositions. First, within both natural fertility populations (identified at the aggregate level) and cohorts following the onset of fertility limitation, we hypothesized that substantial groups of women with long birth intervals across the individually specified childbearing careers could be identified. That is, even during periods when fertility behavior at the aggregate level is consistent with a natural fertility regime, birth intervals at all parities are inversely related to completed family size. Our tabular analysis enables us to conclude that birth spacing patterns are parity dependent; there is stability in CEB-parity specific mean and birth interval variance over the entire transition. Our evidence does not suggest that the early group of women limiting and spacing births was marked by infecundity. Secondly, the transition appears to be associated with an increasingly larger proportion of women shifting to the same spacing schedules associated with smaller families in earlier cohorts. Thirdly, variations in birth spacing by age of marriage indicate that changes in birth intervals over time are at least indirectly associated with age of marriage, indicating an additional compositional effect. The evidence we have presented on spacing behavior does not negate the argument that parity-dependent stopping behavior was a powerful factor in the fertility transition. Our data also provide evidence of attempts to truncate childbearing. Specifically, the smaller the completed family size, the longer the ultimate birth interval; and ultimate birth intervals increase across cohorts controlling CEB and parity. But spacing appears to represent an additional strategy of fertility limitation. Thus, it may be necessary to distinguish spacing and stopping behavior if one wishes to clarify behavioral patterns within a population (Edlefsen, 1981; Friedlander et al., 1980; Rodriguez and Hobcraft, 1980). Because fertility transition theories imply increased attempts to limit family sizes, it is important to examine differential behavior within subgroups achieving different family sizes. It is this level of analysis which we have attempted to achieve in utilizing parity-specific birth intervals controlled by children ever born.(ABSTRACT TRUNCATED AT 400 WORDS)     

Fertility and mortality in Finland since 1750

Summary In this paper the development of fertility and mortality in Finland, and their interrelations with each other and with economic factors is discussed. An analysis by individual years shows that rises and falls in mortality and fertility rates did not always coincide with poor and good harvests. Fertility in Finland decreased slightly at the turn of the eighteenth and nineteenth centuries, but fell sharply over the period 1876-1925. This fall corresponded closely to changes in the death rate, especially for infants, and appears to justify the conclusion that the changes were connected. These population shifts have been called the first and second demographic transitions, of which the latter was the more dramatic. Factors tending to reduce mortality among infants and in other age groups during the second demographic transition are obvious; those underlying the first demographic transition are less clear. In this connection, the importance of breast feeding and campaigns designed to favour the practice are stressed. These helped to reduce infant mortality and were one of the main reasons for the first demographic transition. Finnish material also suggests that some kind of family planning existed during the pre-industrial period; it is only by making this assumption that the various figures can be made compatible.     

Adolescent fertility: worldwide concerns

There is growing concern over the adverse health, social, economic, and demographic effects of adolescent fertility. Morbidity and mortality rates ar significantly higher for teenage mothers and their infants, and early initiation of childbearing generally means truncated education, lower future family income, and larger completed family size. Adolescent fertility rates, which largely reflect marriage patterns, range from 4/1000 in Mauritania; in sub-Saharan Africa, virtually all rates are over 100. In most countries, adolescent fertility rates are declining due to rising age at marriage, increased educational and economic opportunities for young women, changes in social customs, increased use of contraception, and access to abortion. However, even if fertility rates were to decline dramatically among adolescent women in developing countries, their sheer numbers imply that their fertility will have a major impact on world population growth in the years ahead. The number of women in the world ages 15-19 years is expected to increase from 245 million in 1985 to over 320 million in the years 2020; 82% of these women live in developing countries. As a result of more and earlier premarital sexual activity, fostered by the lengthening gap between puberty and marriage, diminished parental and social controls, and increasing peer and media pressure to be sexually active, abortion and out-of-wedlock childbearing are increasing among teenagers in many developed and rapidly urbanizing developing countries. Laws and policies regarding sex education in the schools and access to family planning services by adolescents can either inhibit or support efforts to reduce adolescent fertility. Since contraceptive use is often sporadic and ineffective among adolescents, family planning services are crucial. Such programs should aim to reduce adolescents' dependence on abortion through preventive measures and increase awareness of the benefits of delayed sexual activity. Similarly, sex education should seek to provide a basis for intelligent, informed decision making. Programs tailored to reach teenagers in schools, recreational centers, and the workplace have particular potential.     

Stages of the Demographic Transition from a Child's Perspective: Family Size,Cohort Size,and Children's Resources

This article provides a new characterization of stages of the demographic transition from the perspective of children competing for resources within families and cohorts. In Stage 1 falling mortality increases the size of both families and birth cohorts. In Stage 2 falling fertility overtakes falling mortality to reduce family size, but population momentum causes continued growth in cohort size. In Stage 3 falling fertility overtakes population momentum to produce declining cohort size. We apply our framework to census microdata for eight countries and to United Nations population projections for a larger set of countries. The results suggest that most countries spend two to three decades in Stage 2, with declining family size offset by increasing cohort size. From the perspective of children aged 9–11, many countries enter Stage 3 between 2000 and 2010. Other countries, especially in Africa, will continue to experience increasing cohort size for several more decades.     

How economic development and family planning programs combined to reduce indonesian fertility

This paper examines the contributions of family planning programs, economic development, and women’s status to Indonesian fertility decline from 1982 to 1987. Methodologically we unify seemingly conflicting demographic and economic frameworks into a single “structural” proximate-cause model as well as controlling statistically for the targeted (nonrandom) placement of family planning program inputs. The results are consistent with both frameworks: 75% of the fertility decline resulted from increased contraceptive use, but was induced primarily through economic development and improved education and economic opportunities for females. Even so, the dramatic impact of the changes in demand-side factors (education and economic development) on contraceptive use was possible only because there already existed a highly responsive contraceptive supply delivery system.     

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。     

对中国人口转变的再思考

论文作者通过对数十年来中国人口婚育行为模式、家庭结构与类型、死因构成模式转变的简要描述,指出仅在传统和最基本的人口动态、即人口出生、死亡和增长的角度来理解和认识人口转变、包括中国的人口转变,已远远不够,难以适应时代和人口发展的要求。提出人口转变是一个多维的动态历史过程,是一系列特定人口转变的集合。其中人口出生率、死亡率和自然增长率的变动仅仅是人口转变的表象和外壳,其内核则是通过制度、文化和技术等承载的人口行为及其动力机制,由此引致的变化才代表了人口的内在转变,强调关注人口的内在转变是理解中国特色人口转变道路的重要视角和基础。在对人口转变内涵探索的前提下,借助于对国内人口学界近些年有代表性的人口转变理论研究成果的介绍和分析,作者初步探讨了人口转变理论研究的拓展和创新问题。     

Is Fertility Behavior in Our Genes? Findings from a Danish Twin Study

This article investigates the fertility of Danish twins born during the periods 1870–1910 and 1953–64 in order to pursue two central questions for understanding human reproduction: Do genetic dispositions influence fertility and fertility-related behavior? Does the relevance of the “nature versus nurture” debate shift over time or with demographic regimes? The authors find that genetic influences on fertility exist, but that their relative magnitude and pattern are contingent on gender and on the socioeconomic environment experienced by cohorts. Among females born in 1880–90 and after 1955, about 30–50 percent of the variance in fertility is due to genetic influences; these influences are substantially smaller for earlier and for interim birth cohorts. Male fertility is generally subject to smaller genetic and larger shared-environment effects than female fertility. Because genetic effects are most prevalent in situations with deliberately controlled fertility and relatively egalitarian socioeconomic opportunities, the authors propose that the genetic dispositions affect primarily fertility behavior and motivations for having children. Analyses of fertility motivations, measured by age of first attempt to have a child, support this interpretation.     

Polygyny and the rate of population growth

Summary The roots, motives and feasibility of practising polygyny in societies with a balanced sex structure and the effect of polygyny on the rate of population growth are considered. High demand for labour combined with limited supply over the last several centuries, had been conducive to the evolution of a polygynous nuptiality pattern. The unprecedentedly high rates of population growth during the last several decades combined with progressive economic development have led to a change in the role of the labour factor and consequently diminished its impact upon polygyny. Polygyny is feasible because of a sex-age differential at first marriage, which enables younger cohorts of women to enter the marriage market, and thus results in a very early age at first marriage and universal incidence of marriage among women. A very young pattern of nuptiality inevitably evolves under polygyny, which tends to raise the rate of population growth. No significant variation in fertility between polygynous and monogamous women was found but substantial gaps in standards of living, child mortality, and educational attainment were noted for polygynous households. The findings imply that during the transition from polygyny to monogamy family size will tend to diminish, although initially fertility may not decline concurrently with changing socio-economic status. The most important effects on the rate of population growth thus result from the increase in age at first marriage and declining proportions of ever married women.     

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.     

Aging in the United Kingdom: a review of demographic trends,recent policy developments and care provision

"Although the U.K.'s population is not predicted to grow very much in the future, the population structure is changing and there is a shift towards a much older age distribution. The characteristics of demographic aging in the U.K. include a marked reduction in fertility rates, increasing rates of life expectation at birth..., increasing dependency ratios and variations in mortality and social class in old age. The U.K.'s demographic context has important implications for aged care policy and planning. This paper documents the demographic trends, reviews recent major policy changes and their impact on care provision, and discusses some of the emerging implementation issues that challenge the potential of such policies to meet the needs of an aging population."     

Determinants of national family planning effort

In light of recent research demonstrating a substantial impact of family planning programs on fertility, we develop and estimate a multivariate model of the determinants of national differences in family planning program effort (FPPE). The framework that guides the specification of this model identifies three broad classes of factors—those that create demand for family planning, those that facilitate the initiation and expansion of family planning programs, and finally those that encourage or inhibit program development. The results from multiple regression using 84 less developed countries indicate that demand for family planning, facilitating infrastructure, and certain demographic and geographic factors are important determinants of program effort. These results suggest that popular demand for family planning is helpful, but that policy makers must perceive the adverse consequences of high fertility and have the infrastructure necessary to develop an effective organized family planning program. Current U.S. policies relevant to reducing birth rates are discussed and found to reflect quite well research on determinants of fertility declines among LDCs. U.S. policy also balances the often competing claims of family planners and their opponents by encouraging support to both developmental projects as well as direct aid to family planning program activities.