Birth trajectory under changing fertility conditions

An initially stable population of women is assumed to shift its reproductive behavior to a different level either abruptly or in a prescribed gradual fashion. A closed-form solution which is exact up to about 30 years after the reproductive adjustment is found for the resulting birth trajectory. Exact expressions are also found for the long-time asymptotic behavior of both the birth trajectory and the total population size when the shift in reproductive behavior is to bare replacement level. Accurate approximations to these asymptotic results are then derived and used to illustrate why a growing population continues to grow even after shifting to bare replacement reproductive behavior.     

生育文明与我国未来生育率控制

我国的生育率变化一直以来都与生育文明的发展有着密切的关系。深厚的传统生育文化支持着我国农业社会的高生育水平,这在历史上起到过一定的积极作用,但是庞大的人口数量越来越成为我国经济社会发展的包袱。我国现阶段生育率已经在计划生育政策的控制下,达到了一个较低的标准。但是,这种低生育水平还很不稳定,也不可避免的带来了一些社会问题。随着我国经济发展和社会转型,推进生育文明的发展将成为稳定低生育水平,实现适度人口规模的最好方法。     

Perspectives on family and fertility in developing countries

Abstract Two aspects of the family in relation to fertility in developing countries are discussed: set stratification within the family and extended family networks. As both these are central to J. C. Caldwell's theory of fertility transition, the paper is structured as a critique of his position. Drawing on examples and data from Asia, it is argued that the causal significance of sex stratification for fertility lies in the economic risks it imposes on women, deriving from their dependence on men, rather than, as Caldwell suggests, in the disproportionate gain that men derive from their dominant position within families. While Caldwell and others associate strong extended family networks of mutual obligation and support with persistent high fertility, it is argued here that such systems should, instead, facilitate fertility decline. Close-knit and strong kin networks can be viewed as alternatives to children as sources of insurance, and may facilitate fertility decline by preventing children from becoming the focal point of parental concerns for security.     

Birth and death in cities in the developing world

City dwellers in Sub-Saharan Africa have increased roughly 600% in the last 35 years. Throughout the developing world, cities have expanded at a rate that has far outpaced rural population growth. Extensive data document lower fertility and mortality rates in cities than in rural regions. But slums, shantytowns, and squatters' settlements proliferate in many large cities. Martin Brockerhoff studies the reproductive and health consequences of urban growth, with an emphasis on maternal and child health. Brockerhoff reports that child mortality rates in large cities are highest among children born to mothers who recently migrated from rural areas or who live in low-quality housing. Children born in large cities have about a 30% higher risk of dying before they reach the age of 5 than those born in smaller cities. Despite this, children born to migrant mothers who have lived in a city for about a year have much better survival chances than children born in rural areas to nonmigrant mothers and children born to migrant mothers before or shortly after migration. Migration in developing countries as a whole has saved millions of children's lives. The apparent benefits experienced in the 1980s may not occur in the future, as cities continue to grow and municipal governments confront an overwhelming need for housing, jobs, and services. Another benefit is that fertility rates in African cities fell by about 1 birth per woman as a result of female migration from villages to towns in the 1980s and early 1990s. There will be an increasing need for donors and governments to concentrate family planning, reproductive health, child survival, and social services in cities, particularly in Sub-Saharan Africa, because there child mortality decline has been unexpectedly slow, overall fertility decline is not yet apparent in most countries, and levels of migration to cities are anticipated to remain high.     

On allocating resources for fertility reduction in developing countries

Summary Substantial resources are currently being devoted in attempts to reduce fertility in developing countries. Can their allocation be made more efficient, i.e. more effective per unit of investment? This is an exploratory attempt to apply benefit-cost analysis to various realistic interventions, as judged by knowledgeable experts in the absence of sound empirical information on such impacts. (Such judgements appear to represent essentially the same sort of judgements as are made by policy-makers in the field). The paper concentrates on the methods by which several such analyses are made and illustrates the difficulties and problems encountered, but it also presents certain findings and conclusions of substance that show what results can be derived.     

An analysis of the fertility transition in developing countries]

Most developing countries are in the demographic stage of early mortality, high birth rates and high rates of natural population increase. A characteristic of developing countries is that after World War ii, particularly since the 1960s fertility rates are on the decline, even though they still remain high. The fertility rate of developed countries fell from a 1950 rate of 22.9/1000 to 15/1000 in 1982, a decrease of 34.5%, whereas the fertility rate of developing countries hovered around 43/1000 between 1930-1950, 40.6/1000 during the 1960s and 33/1000 in 1982. Between 1950 and 1982 there was a decrease of 24.8%. But the main reason for this decrease is the decline in the last 20 years of the fertility rates of China and India, whose rates fell 34.9% from 1960-1980. Changes in fertility rates are influenced by the age structure of a country, as seen in the changing age structure of developing countries from 1960-80. For example, an increase in fertility rates was 1 consequence of an increase in the number of fertile women aged 15-45 from 42.6% in 1960 to 44.4% in 1980. Nevertheless, there exists some sort of birth control, whether conscious or subconscious, because the number of births per fertile woman is 3-4 fewer than the 14-15 children a woman can theoretically bear. The reason for changes in fertility rates in developing countries can be traced to marriage and family customs, and even more important, to social and economic factors. For example, Asian, African and Latin American cultures tend to support early marriages. When the fertility rates of developed and developing countries are looked at for a comparable period, then the rate of decrease for developing countries is slower than developed countries. But, if the comparison is made for a transitional period (i.e., industrialization), then the rate of decrease for developing countries is faster than for developed countries. Currently there are 25 developing countries that have attained a fertility rate of 25/1000 or lower, and 52 developing countries with a rate of 35/1000.     

Birth rates decline as neighbors learn from one another how to control fertility

This article refers to a recent article (by Population Council demographer John Bongaarts and University of Pennsylvania sociology professor Susan Cotts Watkins) on strategies for promoting future global fertility decline. The article emphasizes the importance of the process of social interaction as a powerful force that accelerates the pace of demographic transition. The force of social interaction is frequently overlooked. Social interaction operates through personal networks that connect individuals; national channels of interaction connecting social and territorial communities within a country; and global channels connecting countries. Empirical evidence finds that the most important interaction for fertility change occurs in exchanges between personal networks of small communities. When innovative fertility behavior is adopted by a group within a community, then changes are communicated in an ever widening band. It is expected that countries with multiple channels of linked transportation and communication networks and extensive media facilities would experience more rapid fertility decline. Bongaarts and Watkins argue that the extent of a country's links with a global society help determine the timing of its transition to lower fertility. All countries are connected to some extent by ideas, information, or social influence and are at some level of development. When some countries in a region begin their fertility transition, neighboring countries soon follow. Fertility transition occurs even at low levels of development. Fertility decline can occur rapidly, even if socioeconomic development is modest, once the onset of the transition has occurred.     

Birth rate trends and changes in marital fertility in the Netherlands after 1937

The rise in fertility in the Netherlands since 1937 is examined in the light of new statistical information which has recently become available. The conclusion reached is that a continuance of the high fertility rates of the recent past is unlikely.     

Completing the fertility transition in the developing world: The role of educational differences and fertility preferences

This study summarizes patterns of educational differentials in wanted and unwanted fertility at different stages of the fertility transition. The data are from Demographic and Health Surveys in 57 less developed countries. As the transition proceeds, educational differentials in wanted fertility tend to decline and differentials in unwanted fertility tend to rise. An assessment of fertility patterns in developed and less developed countries with low fertility concludes that these differentials are likely to remain substantial when less developed countries reach the end of their transitions. This conclusion implies that the educational composition of the population remains a key predictor of overall fertility in late transitional countries and that low levels of schooling can be a cause of stalling fertility.     

Completing the fertility transition in the developing world: The role of educational differences and fertility preferences

This study summarizes patterns of educational differentials in wanted and unwanted fertility at different stages of the fertility transition. The data are from Demographic and Health Surveys in 57 less developed countries. As the transition proceeds, educational differentials in wanted fertility tend to decline and differentials in unwanted fertility tend to rise. An assessment of fertility patterns in developed and less developed countries with low fertility concludes that these differentials are likely to remain substantial when less developed countries reach the end of their transitions. This conclusion implies that the educational composition of the population remains a key predictor of overall fertility in late transitional countries and that low levels of schooling can be a cause of stalling fertility.     

Fertility differentials as evidence of incipient fertility decline in a developing country

Abstract Age data from the 1960 and earlier censuses of Ghana allow the construction of child-woman ratios which appear to indicate the existence of a substantial urban-rural fertility differential. Plausible assumptions of urban-rural mortality differentials increase the apparent fertility differential. In this paper recently published data for Statistical Areas in the country's larger towns are used to demonstrate that one explanation for the fertility differential is almost certainly the enumeration of some females in the towns, while one or more of their surviving children were enumerated outside. Nevertheless, in 1960 the four largest towns exhibited birth levels which are likely to have been about 11% below those of the population in the surrounding regions. Roughly half the differential can be attributed to a general urban-rural differential and half to socio-economic differentials within the towns. It is shown that most fertility reduction within the towns may be explained by delayed female marriage, and that such delay is associated with extended education. It is also shown that amongst the higher socio-economic status groups a small part of the reduction can probably be attributed to the prevention of pregnancy within marriage, and that the making of such attempts is positively associated with extended education, urban birth, participation in first and monogamous marriages, Protestantism, and the holding of views about the harmful effect of high population growth rates on attempts to raise living standards. It is argued that these fertility differentials are evidence of some fertility decline among key groups in the population and that such declines are likely to become more widespread.     

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)     

Bulletin of major figures from manual tabulation of the national sample survey on fertility and birth control of China

The State Council, the State Family Planning Commission, the State Statistical Bureau, the State Planning Commission, the Ministry of Finance, and the Ministry of Public Security of China together carried out a national sample survey on fertility and birth control in China in 1988. The survey was carried out in 30 provinces, autonomous regions, and municipalities directly under the Central Government. The Tibetan Autonomous Region and the Hainan Province were surveyed for the 1st time, but the results from Tibet were not collected in time for this publication. The main respondents were the married women at age 15-57, with 2,114,591 people surveyed and a sampling proportion of 1.98/1000. This article describes the survey and its results according to birth rate, parity composition, and rural-urban fertility differences. Birth rates, mortality rates, and natural increase rates from high to low orders were tabulated for: urban areas, farms, towns, rural townships, and suburban townships. With the first 1/2 of 1988 birth rates tabulated, it was estimated that the total number of births in China will be less than in 1987. In 1987, the rate of 3rd or higher parity birth was below 5% in 6 provinces and municipalities, but 10 provinces and autonomous regions were over 20%. Fertility rates showed considerable disparity depending on the locational demographics (e.g. birth rates in urban areas were 14.3/1000 yet birth rates were 24.3/1000 in suburban townships).     

The fertility impact of changes in the timing of childbearing in the developing world

This study examines the role of tempo effects in the fertility declines of less developed countries. These effects temporarily inflate the total fertility of a population during periods when the age at childbearing declines and deflate it when childbearing is postponed. An analysis of data from the World Fertility Surveys and the Demographic and Health Surveys demonstrates that fertility trends observed in many less developed countries are likely to be distorted by changes in the timing of childbearing. In most countries women are delaying childbearing, which implies that observed fertility is lower than it would have been without tempo changes. This pattern is most clearly documented in Taiwan, where accurate birth statistics from a vital registration system make it possible to estimate the tempo components of fertility annually from 1978 to 1993. The small but unexpected rise in the total fertility of Colombia in the early 1990s is attributed to a decline in the negative tempo distortion that prevailed in the 1980s. Similar interruptions of ongoing fertility declines may occur in the future in other countries when existing negative tempo effects are removed.     

Trade and fertility in the developing world: the impact of trade and trade structure

In the literature on trade and development, fertility and trade have been widely discussed as two separate economic forces. However, an important recent contribution connects these two and suggests that international trade between developed and developing countries has an asymmetric effect on the demand for human capital. The asymmetry leads to a decline in fertility rates in developed countries and an increase in these rates in developing countries. We provide additional comprehensive empirical evidence in support of this novel hypothesis. Our findings suggest that countries that export skill-intensive manufacturing goods experience a decline in fertility rates, whereas in countries that export primary, low-skill-intensive goods, fertility rates are affected positively. Further, our findings indicate that the negative influence of manufacturing exports on fertility holds primarily and most strongly for middle-income countries where structural modernization and a growing manufacturing-intensive export sector is observed.     

Different features and conditions of the fertility transition in the developed countries and the developing countries]

Differences between the demographic transition experienced by developed countries and that currently being experienced by developing countries are first discussed. The author then stresses the need for developing countries to lower fertility in order to foster socioeconomic development, rather than waiting for economic development to bring about reductions in fertility.