On Postponement and Birth Intervals

Much of the literature on fertility transition presumes that birth control is practiced either to limit family size or to space births. This article argues that women also use birth control to postpone pregnancy. Postponement is not synonymous with spacing. It arises when women delay their next birth for indefinite periods for reasons unrelated to the age of their youngest child, but without deciding not to have any more children. Postponement has a distinctive impact on the shape of birth‐interval distributions that differs from the impacts of family size limitation, birth spacing, or a mixture of the two behaviors. Some populations, such as that in South Africa, have developed fertility regimes characterized by birth intervals far longer than can be accounted for by birth spacing. Postponement of further childbearing that eventually becomes permanent may be an important driver of the transition to lower fertility in sub‐Saharan Africa.     

Maternal Education, Birth Weight, and Infant Mortality in the United States

This research determines whether the observed decline in infant mortality with socioeconomic level, operationalized as maternal education (dichotomized as college or more, versus high school or less), is due to its “indirect” effect (operating through birth weight) and/or to its “direct” effect (independent of birth weight). The data used are the 2001 U.S. national African American, Mexican American, and European American birth cohorts by sex. The analysis explores the birth outcomes of infants undergoing normal and compromised fetal development separately by using covariate density defined mixture of logistic regressions (CDDmlr). Among normal births, mean birth weight increases significantly (by 27–108 g) with higher maternal education. Mortality declines significantly (by a factor of 0.40–0.96) through the direct effect of education. The indirect effect of education among normal births is small but significant in three cohorts. Furthermore, the indirect effect of maternal education tends to increase mortality despite improved birth weight. Among compromised births, education has small and inconsistent effects on birth weight and infant mortality. Overall, our results are consistent with the view that the decrease in infant death by socioeconomic level is not mediated by improved birth weight. Interventions targeting birth weight may not result in lower infant mortality.     

出生性别比偏高的特征与原因分析——对湖北省麻城、广水、安陆三市的调查

湖北省麻城、广水、安陆三市总出生性别比升高呈现出的特征:一孩出生性别比基本正常或略微高些,但二孩及以上出生性别比超高,而二孩出生性别比超高是总出生性别比升高的主要原因;政策内二孩生育存在严重男孩性别选择行为;贫困农民家庭是选择性男孩生育的主要群体;性别选择最容易在农村流出育龄人群中实现。农村经济社会文化环境、农民家庭多重生育需求、男孩偏好、生育性别选择,这些环环相扣的因果关系变量,以及胎儿性别鉴定与人工终止妊娠易获得性和现行生育政策的“挤压”效应等,是造成调查地出生性别比异常的综合因素。     

Health Endowment at Birth and Variation in Intergenerational Economic Mobility: Evidence From U.S. County Birth Cohorts

New estimates of intergenerational economic mobility reveal substantial variation in the spatial distribution of opportunity in the United States. Efforts to explain this variation in economic mobility have conspicuously omitted health despite it being a key pathway for the transmission of economic position across generations. We begin to fill this gap in the literature by examining the relationship between health endowment at birth and intergenerational economic mobility across county birth cohorts in the United States, drawing on estimates from two population-level data sets. Exploiting variation across counties and over time, we find a negative relationship between the incidence of low-weight births and the level of economic mobility as measured in adulthood for the county birth cohorts in our sample. Our results build on a large and growing literature detailing the role of early childhood health in the transmission of economic status across generations and suggest that the incidence of low-weight births is negatively associated with intergenerational economic mobility.     

Fertility Following an Unintended First Birth

Research on unintended fertility tends to focus on births as isolated events. This article expands previous research by examining the relationship between early unintended childbearing and subsequent fertility dynamics in the United States. Data from the 2002 National Survey of Family Growth show that 27.5% of mothers report an unintended first birth. We use event history methods to show that these women are significantly more likely than women with an intended first birth to have an unintended second birth than to have either no second birth or an intended second birth, net of sociodemographic characteristics. An unintended first birth also increases the risk of having an unintended third birth relative to no birth or an intended birth, independent of the intendedness of the second birth. We conclude that early unintended fertility is a strong signal of high risk for subsequent unintended fertility.     

Maybe Next Month? Temperature Shocks and Dynamic Adjustments in Birth Rates

We estimate the effects of temperature shocks on birth rates in the United States between 1931 and 2010. We find that days with a mean temperature above 80°F cause a large decline in birth rates 8 to 10 months later. Unlike prior studies, we demonstrate that the initial decline is followed by a partial rebound in births over the next few months, implying that populations mitigate some of the fertility cost by shifting conception month. This shift helps explain the observed peak in late-summer births in the United States. We also present new evidence that hot weather most likely harms fertility via reproductive health as opposed to sexual activity. Historical evidence suggests that air conditioning could be used to substantially offset the fertility costs of high temperatures.     

Duration of Marriage,Fertility and Women's Employment Opportunities in England and Wales in 1911

Data from the 1911 Census of England and Wales are examined for evidence of family limitation early in marriage. It is shown that a substantial number of couples used birth control for ‘spacing’ as well as for ‘stopping’ fertility. Moreover ‘spacing’ of births appears to have been more widespread in districts in which women's employment opportunities were relatively good. In general, the results obtained do not fit with the Princeton view of the European fertility transition with its stress on parity-specific family limitation spreading in response to improvements in contraceptive information and technology.     

出生性别比升高的分因素贡献率

文章根据2005年1%人口抽样调查数据,对比2000年人口普查数据,利用经济学中的贡献率概念,给出分因素出生人口性别比升高的贡献率计算方法,比较在全国出生性别比升高中各省的贡献及在各省出生性别比升高中分城乡及分孩次的贡献程度,为做好综合治理出生性别比工作提出新的观点和建议。     

Birth outcome, not pregnancy process: Reply to van der Veen

In a recent article (Frisbie. Forbes. and Pullum 1996) we documented racial/ethnic differences in birth outcomes according to a more fine-grained classification than has typically been employed in the demographic literature. In his commentary, van der Veen focuses on the measurement of one of the dimensions of that classification, maturity of the infant. as proxied by the fetal growth ratio. The crux of the critique is easily seen in van der Veen's statement that “all of my disagreements with Frisbie et al. 's method arise from their particular use of a postnatal standard for the assessment of intrauterine growth.” Our critic misunderstands our objective: He fails to realize our interest in birth outcome, not pregnancy process, and does not perceive that our intent was to extend the research extant in both the demographic and public-health literatures in which patently postnatal (i.e., ex utero) measures are taken as outcomes interesting in their own right and/or as risk factors for infant mortality and infant and childhood morbidity. Specifically, he does recognize that we purposefully expanded our focus to include moderately compromised births to determine if they were at higher risk than the normal births with whom they are conventionally categorized. Our discussion draws on research cited in the original article, on studies cited by our critic, and on a few more recent investigations. Although we have never argued that ours is the only, or even the best, approach in all cases, we try to clarify the rationale for, and adduce additional empirical evidence of, the utility of the method we used.     

How many children? – Fixing total annual births as a population control policy

Traditional family planning's emphasis on manipulating the total fertility rate often results in erratic number of births which disrupts school enrollment and labor supply. Fixing total annual births to a permanently lower level will avoid such repeated disruptions and can eventually lead to a lower stationary population with annual deaths equal to the fixed annual births. If allocation of the fixed birth quotas is conditional upon deaths, each death can be converted to a variable number of inheritable and tradable birth quotas. Tradable birth coupons allow families to have the number of children they want and can afford within the overall fixed birth quotas. Inheritable birth quotas provide incentive for higher old-age mortality and consequently less aging in a declining population.     

关注大城市低生育水平下的出生人口波动

根据上海户籍人口变动趋势的预测数据 ,具体分析出生人口波动引起的未来年出生人数“大起大落”的状况及其对产科床位、托儿所、幼儿园、小学、初中、高中乃至大学发展所带来的重大负面影响。建议各地计生部门应在稳定低生育水平的同时 ,密切关注未来大城市户籍人口出生数的波动态势 ,加强未来出生人口波动的预测和预报 ,对现行生育政策作些“微调” ,因地制宜地搞好未来出生人口“削峰补谷”的宏观调控 ,引导年轻育龄夫妇通过适当提前或推迟生育 ,减缓未来城市户籍出生人数的波动。     

Female work experience,employment status,and birth expectations: Sequential decision-making in the Philippines

The influence of women’s birth parity and accumulated market skills on their current labor force participation and birth expectations is examined within a sequential choice framework, Analysis of household data from the 1973 Philippines National Demographic Survey suggests these patterns: (a) women who have accumulated larger families work less in the current period and anticipate fewer additional births; (b) women with more past work experience tend to work more hours in the current period; and (c) work experience appears to have only a weak negative effect on birth expectations among older women.     

Assesssing Cohort Birth Expectations Data from the Current Population Survey, 1971–1981

Data from the fertility supplements to the Current Population Survey from 1971 to 1981 indicate that in the aggregate, the lifetime birth expectations of married women 18 to 39 years old in 1971 will closely approximate their completed cohort fertility. During this period, the youngest group of women, 18 to 24 years old, delayed their childbearing; their short-term expectations (1971–76) were not realized, but they made up enough births in the latter half of the decade to enable them to attain their lifetime birth expectations. In retrospect, the “failure” of birth expectations data to predict the “period” fertility downswing in the 1970s resulted not from poor predictions of married women, but rather from unanticipated marital and subsequent childbearing patterns of women who were single at the beginning of the decade. The authors conclude that birth expectations are useful predictors of completed cohort fertility, if adjustments are made to incorporate changes in the proportions married within the birth cohort.     

Put the planned birth propaganda and education in number 1 place: a summary of a conference]

The Planned Birth Office of the Chinese State Council convened a National Planned Birth Propaganda Symposium in Beijing from January 10 to 14, 1981. There were over 50 representatives from various provincial, municipal, autonomous regional planned birth offices, Shanghai, Beijing, and Chengdu's Planned Birth Propaganda and Education Centers, the Central Cultural, Education and Public Health Ministries, and various population research centers, and journalists. The Vice-premier of the Chinese State Council, Chen Muhua made the following points in an address to the delegates: planned birth is a longterm project; the 2-fold character of production, i.e., material production and human reproduction, must be properly understood; the goal of limiting China's population to 1,200,000,000 is difficult, so everyone must plan for their families by understanding the work of birth planning early, carefully, and securely, and further that late marriage, late births, few births, and superior births must be advocated the attitude that families without sons will have no heirs must be abolished because girls are heirs too; the fear that China will become an aged society must be ameliorated because China's age structure is a young one. Wang Renchong, Chairman of the Central Propaganda Ministry, also addressed the Symposium. He remarked that with a population approaching 1 billion, 80% of whom are peasants, population control is crucial to the nation's health and survival and is an important part of the Four Modernizations. Birth planning propaganda and education must be given top priority, especially in rural areas. The chairman of the Planned Birth Office of the Chinese State Council closed the meetings by saying that birth planning work must rely on the Party and governmental policies, and especially on propaganda.     

Reexamining the Dominance of Birth Cohort Effects on Mortality

The association between birth cohort and subsequent mortality has been of interest especially following publication of studies around 1930 of cohorts born up to the latter part of the nineteenth century, particularly for England and Wales. Updated results are presented for this population, together with those for two other cohorts, twentieth‐century Japanese and British populations born about 1930, which have been identified as having particularly clear‐cut birth cohort patterns, and which are used to underpin incorporation of cohort effects in both British official and actuarial mortality forecasts. Graphical methods used to identify cohort patterns are discussed. A number of limitations and difficulties are identified that mean that the conclusions about the predominance of cohort effects are less robust than often assumed. It is argued that alternative explanations should be considered and that the concentration on birth cohorts with particularly advantaged patterns may distort research priorities.     

Family size and educational attainment in England and Wales

In this paper, we use linked census data from England and Wales to investigate whether having a large number of siblings leads to lower educational attainment. There is a large literature suggesting that with large sibship size, parental resources will be diluted and this, in turn, will lead to lower educational attainment. Using twin births and the sex composition of the sibling group as instrumental variables, we find that the evidence of a family size effect on educational attainment is rather uncertain. Similar results are obtained when we use occupational attainment as the dependent variable. We also demonstrate the confounding of birth order and family size effects, and show that an adjusted birth order index proposed by Booth and Kee provides an effective solution to this estimation problem.     

Regression analysis of the relationship between the birth rate and proportion of first order births in 1981]

Generally speaking, various fertility indicators such as the birth rate, average fertility rate, and total fertility rate have a close relationship. Various regression analyses have also been made by using different data on population statistics to describe their internal relationships. A regression analysis of the relationship between the birth rate and proportion of first order births, however, has not been made. Data collected by family planning staff at various places show that the places with a high rate of first order births normally have a lower birth rate, and the places with a low rate of first order births very often have a high birth rate. From here we may find that the proportion of the first order births is moving in two opposite directions, and there is no determined relationship between them. It is impossible to use one indicator to calculate the other's indicator. Only a regression analysis can be made to study the relationship between the two. The birth rate and proportion of first order births in 1981 showed some negative relationship, but the use of a regression equation should still be restricted. The regression equation between the birth rate and proportion of first order births may reflect a correct relationship when the region and the number of first order births are fixed. Therefore, any factor which has an impact on the number of first order births also has an influence on the use of regression equation.     

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)     

What’s happening to the age at first birth in the United States? A study of recent cohorts

This paper analyzes cross-cohort trends in the age pattern of women at first birth in the United States. The analysis involves fitting the Coale-McNeil marriage model to the age distribution of first birth frequencies for a number of recent white and nonwhite cohorts. Methodologically, the results (a) provide support for the application of the Coale-McNeil marriage model to first birth data, and (b) demonstrate the ability of the model to accurately project first birth fertility for cohorts which have yet to complete their childbearing years. Substantively the results indicate (a) that the proportion of women who will never have a first birth is increasing across cohorts and can be expected to be as high as .25 and .20 for recent white and nonwhite cohorts respectively; (b) that recent nonwhite cohorts have an appreciable number of first births at earlier ages than their white counterparts, as well as a lower mean age at first birth and increasingly less dispersion (across cohorts) in their age at first birth; and (c) that the mean age at first birth and the proportion of first births occurring between ages 25 and 34 is increasing across cohorts of white women but is stable across cohorts of nonwhite women.     

A preliminary inquiry about the problem of second births outside the plan]

In 1981, the population growth in China was revived and showed a new trend towards a rapid increase. In general, the rate of numerous births in one household was down, the rate for a second birth outside the plan was up sharply, and the number for a second birth outside the plan exceeded the number for multiple births in average families. As a result, how to control the second birth outside the plan has become a crucial problem for population control. Under present conditions, numerous births in each household are normally related to the financial situation of each household, the sex of earlier births, and the educationa background of the parents. The current increase in second births is not caused by financial reasons. Instead, it is caused by social and psychological reasons. The traditional belief in favor of having more male children for security in one's old age and for continuation of one's family line is still deeply rooted in the people's minds. In order to eliminate such tradtional influence, more work in ideological education is needed so that the common people may understand the need for birth control and change their traditional view on population. With the establishment of a responsible production system in the rural areas, measures for economic restriction and reward should be taken. In addition, late marriages should be enouraged, and a new tax system based upon population count in each household should be adopted so that additional revenues may be collect for educational and other expenses, and social insurance for old people should be expanded. If all these measures are taken successfully, the problem of second births outside the plan can be solved.