Birth Intervals and Childhood Mortality in Rural Bangladesh

This study investigates the relationship between birth intervals and childhood mortality, using longitudinal data from rural Bangladesh known to be of exceptional accuracy and completeness. Results demonstrate significant but very distinctive effects of the previous and subsequent birth intervals on mortality, with the former concentrated in the neonatal period and the latter during early childhood. The impact of short birth intervals on mortality, however, is substantially less than that found in many previous studies of this issue, particularly for the previous birth interval. The findings are discussed in terms of the potential for family planning programs to contribute to improved child survival in settings such as Bangladesh.     

Distribution of Closed Birth Intervals in a Heterogeneous Population

The probability distribution of parity-specific closed birth intervals in a heterogeneous population of women is obtained from Biswas' (1980) concept of gradually decreasing fecundabilities. The distribution of parity-specific last closed birth intervals and its moments of various orders are derived for a heterogeneous female population. Simulations are used to compare with models for a homogeneous female population with constant fecundability. The consideration of heterogeneity allows a better fit for empirical closed birth intervals.     

农村二孩生育间隔的分层模型研究

2001年全国计划生育/生殖健康调查数据本质上是分层结构性质的,其中包括妇女个人数据和村级数据两个层次,比较适合采用分层模型分析。本文应用分层线性模型分析了这一原始数据,考察宏观的社会经济环境及计划生育氛围与微观的妇女个人特征如何共同影响二孩生育间隔。     

Determinants of Korean Birth Intervals: The Confrontation of Theory and Data

In this analysis, data from the Korean National Fertility Survey of 1974 are used to seek to explain differences in the pace of fertility in terms of differences in contraception, breastfeeding and other intermediate variables. Strong effects are found for these variables, particularly contraception. Nonetheless, virtually none of the effects of the socio-economic variables can be explained in our full model. Overall, our first models, which included only the socio-economic variables, contained 44 significant coefficients. With the introduction of the intermediate variables, only eleven of these coefficients became non-significant (while six others became significant). Thus, though using excellent data, we cannot begin to reproduce what theory predicts. The analysis suggests that this is a consequence of both measurement error and omitted intermediate variables, such as coital frequency. There are strong theoretical reasons for attempting to elucidate the mediating role of proximate variables by using individual data. Nonetheless, these findings, together with similar results obtained by others, strongly suggest that this is not likely to be a fruitful line of future endeavour.     

Birth Intervals and Health in Adulthood: A Comparison of Siblings Using Swedish Register Data

A growing body of research has examined whether birth intervals influence perinatal outcomes and child health as well as long-term educational and socioeconomic outcomes. To date, however, very little research has examined whether birth spacing influences long-term health. We use contemporary Swedish population register data to examine the relationship between birth-to-birth intervals and a variety of health outcomes in adulthood: for men, height, physical fitness, and the probability of falling into different body mass index categories; and for men and women, mortality. In models that do not adjust carefully for family background, we find that short and long birth intervals are clearly associated with height, physical fitness, being overweight or obese, and mortality. However, after carefully adjusting for family background using a within-family sibling comparison design, we find that birth spacing is generally not associated with long-term health, although we find that men born after very long birth intervals have a higher probability of being overweight or obese in early adulthood. Overall, we conclude that birth intervals have little independent effect on long-term health outcomes.     

The Long-Term Cognitive and Socioeconomic Consequences of Birth Intervals: A Within-Family Sibling Comparison Using Swedish Register Data

We examine the relationship between birth-to-birth intervals and a variety of mid- and long-term cognitive and socioeconomic outcomes, including high school GPA, cognitive ability, educational attainment, earnings, unemployment status, and receiving government welfare support. Using contemporary Swedish population register data and a within-family sibling comparison design, we find that neither the birth interval preceding the index person nor the birth interval following the index person are associated with any substantively meaningful changes in mid- or long-term outcomes. This is true even for individuals born before or after birth-to-birth intervals of less than 12 months. We conclude that in a contemporary high-income welfare state, there appears to be no relationship between unusually short or long birth intervals and adverse long-term outcomes.     

The Effect of Imputation Procedures on First Birth Intervals: Evidence from Five African Fertility Surveys

In most African societies there is little motivation to remember dates of demographic events with the level of precision required in demographic surveys. Consequently it is common that the large majority of survey respondents can provide only the calendar year of occurrence or their age at the time of the event. The World Fertility Survey Group decided to handle the problem of poor date reporting by using a computer program to impute the missing information. This article illustrates the effect of these imputation procedures on cross-national differentials in the proportion of premarital first births in Benin, Cameroon, Cote d’Ivoire, Ghana, and Nigeria. The analysis demonstrates that the exceptionally low proportion of premarital first births in Ghana is an artifact of the imputation procedures.     

Childbearing in Italy and Spain: Postponement Narratives

Italy and Spain are extreme cases of low fertility linked to postponement of childbearing. Demographers continue to debate causes of postponement. This qualitative study was designed to contribute, by purposively selecting Italian and Spanish women in different socio-economic circumstances who are partnered, childless and aged 30 to 35. Most want children but “not now” or are deferring the decision whether to have children. Their different circumstances inflect explanations of postponement in a language of choice, either “taking time” to achieve other goals or “holding on” for conditions to change. They are encouraged to postpone by optimism about their capacity to conceive, flexible norms about “the right age,” prolonged dependence on their parents, the normative salience of “total motherhood,” and family-unfriendly, gender-unequal workplaces. Elements of competing demographic theories often coexist in interviewees' accounts. The “desires-intentions gap” does not always capture their flow or complexity.     

A Cohort Model of Fertility Postponement

We introduce a new formal model in which demographic behavior such as fertility is postponed by differing amounts depending only on cohort membership. The cohort-based model shows the effects of cohort shifts on period fertility measures and provides an accompanying tempo adjustment to determine the period fertility that would have occurred without postponement. Cohort-based postponement spans multiple periods and produces “fertility momentum,” with implications for future fertility rates. We illustrate several methods for model estimation and apply the model to fertility in several countries. We also compare the fit of period-based and cohort-based shift models to the recent Dutch fertility surface, showing how cohort- and period-based postponement can occur simultaneously.     

Period Parity Progression Ratios and Birth Intervals in England and Wales, 1941–1971: A Synthetic Life Table Analysis

A method is presented for analysing maternity history data to provide period estimates of parity progression ratios, birth intervals and related indices. This is applied to a sample of the marriage and maternity histories from the Census of England and Wales of 1971 and shows: (a) a general increase through the 1950s and into the 1960s in period estimates of marriage and parity progression ratios, especially in the progression from first to second birth; (b) a general acceleration of fertility with, again, the second birth interval becoming particularly short and compact; and (c) very steep declines in third and fourth birth progression ratios from the mid-1960s. Birth interval distributions altered during the period examined. Decomposition of a progression-based total fertility index shows change in the ratios for lower birth orders to have dominated the fertility upswing and declines in ratios for higher birth orders to have initiated the subsequent decline.     

我国妇女生育推迟与近期生育水平变化

随着我国时期生育水平的下降,我国妇女的平均生育年龄自20世纪90年代以来呈现上升的趋势。在这样的情况下,传统的时期总和生育率的估计受到进度效应的影响,人们从这一指标中难以对我国近期生育水平的变化形成正确的认识。本文利用多来源可靠数据,对我国近期的总和生育率以及去进度效应总和生育率进行了估计,发现去除进度效应影响后,生育水平的时期估计值有了大幅度上升,2007²012年的生育水平大约在1.7至1.8之间。研究进一步重构了19642012年的生育水平大约在1.7至1.8之间。研究进一步重构了1964¹985年出生队列的部分年龄别生育率,发现年轻队列的峰值年龄别生育率较低,但在较高年龄时会出现年龄别生育率相较之前队列升高的现象。文章进一步探讨了我国生育政策对于妇女生育行为的影响以及政策变动可能带来的时期生育率的变化。     

Masculinity,Money, and the Postponement of Parenthood in Nigeria

In southeastern Nigeria, several interconnected processes of social change are combining to delay parenthood. Most of the demographic and social sciences literature examining the postponement of parenthood has paid primary attention to women. To address this gap, this article foregrounds the changing social landscape of masculinity as a significant context within which to situate these demographic changes. At the core of Nigerian men's perceptions, decisions, and behaviors with regard to delaying fatherhood is a fundamental contradiction, one that seems to be common in many settings—at least many African settings—of contemporary demographic transition. The contradiction is that while the postponement of parenthood is associated historically with positive social and economic indicators, when Nigerian men articulate their rationales for delaying fatherhood (and marriage) they commonly describe feelings of uncertainty connected to a sense of struggle and deprivation. This article connects men's anxieties about—and delays embarking on—marriage and parenthood to their experiences of economic uncertainty, and specifically to the perceived need for money as the foundation for successful reproduction.     

生育控制与第四种国家的出路

20世纪30年代,我国人口社会学家如吴景超、陈达等力倡生育控制,人口众多的我国列为第四种国家。人口的发展不是孤立的人口问题本身,而是与经济社会发展相一致,保持人口的外部均衡,在此基础上,力求人口内部结构保持平衡。当前我国发展的主要任务是促进产业升级转型,注重经济发展质量,而这正需要人口减少和优化。     

平均预期寿命、健康工作寿命与延迟退休年龄

我国劳动者能健康工作多久?退休年龄究竟延迟到哪一岁最为合理?这关系着广大劳动者切身利益因而是非常重大的政策性问题。本研究采用生命表技术编制了我国2005和2010年分性别人口平均预期寿命、健康预期寿命、工作寿命及健康工作寿命表,然后从劳动力健康工作的视角提出我国延迟退休的合理目标年龄。研究发现,2005和2010年,我国男女健康工作寿命都分别接近62岁和58岁。该发现的重要政策启示在于:我国当前可适当延迟退休年龄,女性比男性延迟退休的空间大,男女65岁同龄退休的时机还未成熟,建议我国延迟退休的目标年龄应以男性62岁,女性58岁为上限;从生命周期角度对我国退休年龄进行国际比较,若按男性62岁,女性58岁为退休年龄上限执行,那么我国劳动力的退休生涯与工作寿命之比将接近发达国家的平均水平;从政策的操作层面来看,我国延迟退休应女先男后或女快男慢,并采取弹性退休制度逐步推迟退休年龄。     

对我国当前推迟退休年龄之说的质疑

随着我国老年型社会的到来和老龄化速度的加快 ,人口老龄化对社会经济的影响问题受到了极大的关注。目前我国学术界的一种观点认为 :由于我国老龄化的速度加快和人口平均预期寿命的延长 ,相应的老年人口负担加重 ,劳动力资源也必然减少 ,为此必须推迟退休年龄 ,才能适应老龄化社会发展的需要。依据这些理由提出推迟退休年龄有失偏颇 ,就我国当前情况而言 ,全面推迟退休年龄还不合时宜     

民族地区出生人口性别比状况分析及对策研究

本文以"四普"、"五普"数据为基础,结合近年来湘西州出生人口性别比调查数据,对湘西州少数民族人口出生性别比状况进行分析,提出治理民族地区出生人口性别比失衡的对策,为民族地区人口与经济社会的和谐发展做出思考。     

On Das Gupta's ‘Birth function in a two-sex model’

I have read with great interest Das Gupta's¹ critique of my approach² towards the development of a two sex-model. To set the records straight, I must state that his criticisms are not well founded due to the following reasons:     

怀孕年龄与胎次对出生缺陷的影响分析

本研究通过抽取浙江大学医学院附属妇产科医院某病区5782个病例(736例患病),从出生缺陷的角度,通过对妇女怀孕年龄及胎次与胎儿畸形患病率的关系对开放二胎政策之后的人口质量的影响进行分析,发现孕妇年龄过低(19岁以下)与过高(35岁以上)均会导致出生缺陷率提高;而胎次的影响比较复杂,对于24岁以下的年龄段来说,胎次越高,患病率越高,而对于25-44岁的孕妇来说,除了第4胎及以上的患病率较高,第2、3胎的患病率没有明显的差别。因此,放开二胎将不会对人口质量产生显著影响。     

Birth control and its determinants

"The article presents the results of the three family [sample] surveys [in Poland]: 'Newlyweds Survey 1985', 'Family Survey 1987'...and 'Determinants and Consequences of Divorces'.... The subject of this article is: the methods of birth control which were used during married life, their moral evaluation and opinions about abortion.... This article indicates the influence of an unhappy marriage and of different phases of family life on the attitudes and opinions about birth control."