Early Childbearing and Child Marriage: An Update.

Eliminating child marriage is seen by policy makers and advocates as a path toward reducing births to girls below age 18, as most early births have been previously found to occur within marriage. There has been little recent evidence, however, of the marital context in which early childbearing occurs or how this relationship varies across space and levels of development. Using survey and vital registration data covering approximately 95 percent of the world's births to mothers younger than 18 years, we estimated the share of first births that occur within marriage at the global, regional and national levels. We found that more than half of births to mothers below age 18 worldwide take place in sub-Saharan Africa, and this share will continue to grow. Globally, 76 percent of first births to mothers below age 18 occur within marriage and there are large regional differences. Over the past two decades, the share of first births to mothers below age 18 occurring within marriage declined in most countries with data available, but there are important exceptions. Although most first births to women below age 18 occur following seven months of marriage, the sequencing of child marriage and early childbearing varies widely across countries.

Family Size and Educational Attainment: Cousins, Contexts, and Compensation.

This paper analyses the effect of family size on children's educational attainment using a new research design that combines fixed effects and instrumental variable (IV) approaches. We use (a) data on first cousins who belong to the same extended family but to different nuclear families to control for extended family fixed effects and (b) variation in in-married spouses' number of siblings (a proxy for their fecundity and preferences) as an IV for variation in family size within extended families. We find that family size has a negative causal effect on educational attainment and, moreover, that the negative effect is smaller in families with stronger social ties. Our results suggest that contextual characteristics outside the nuclear family moderate the negative effect of family size on children's educational attainment.

Breast-feeding During Pregnancy and the Risk of Miscarriage.

CONTEXT: Breast-feeding rates and durations have been increasing among U.S. women in recent decades. As a result, women may be more likely to practice breast-feeding during pregnancy (BDP), which has been hypothesized to increase the risk of miscarriage, yet there has been little research into the issue. METHODS: Data on 10,661 pregnancies from several waves of the National Survey of Family Growth, covering the years 2002-2015, were used to calculate unadjusted miscarriage rates according to BDP status. Multivariate Cox proportional hazards models were employed to investigate the association between BDP and the risk of miscarriage. RESULTS: BDP was practiced for 6% of the total time at risk of miscarriage. The miscarriage rate was higher when mothers exclusively breast-fed during pregnancy (35%) than when they practiced either complementary BDP (i.e., the child also consumed other food) or did not breast-feed (14% and 15%, respectively). After adjustment for maternal and pregnancy characteristics, the risk of miscarriage was greater when mothers exclusively breast-fed than when mothers did not breast-feed (hazard ratio, 3.9), but no increased risk was found with complementary BDP. The miscarriage risk during exclusive BDP was similar to that for women who conceived when they were 40 or older (3.2). CONCLUSIONS: Exclusive BDP is associated with an elevated risk of miscarriage, but it remains unclear whether and how the practice is associated with health outcomes for the mother and breast-fed child. Research is needed to further explore these outcomes to inform recommendations regarding BDP.

When and Where Birth Spacing Matters for Child Survival: An International Comparison Using the DHS.

A large body of research has found an association between short birth intervals and the risk of infant mortality in developing countries, but recent work on other perinatal outcomes from highly developed countries has called these claims into question, arguing that previous studies have failed to adequately control for unobserved heterogeneity. Our study addresses this issue by estimating within-family models on a sample of 4.5 million births from 77 countries at various levels of development. We show that after unobserved maternal heterogeneity is controlled for, intervals shorter than 36 months substantially increase the probability of infant death. However, the importance of birth intervals as a determinant of infant mortality varies inversely with maternal education and the strength of the relationship varies regionally. Finally, we demonstrate that the mortality-reducing effects of longer birth intervals are strong at low levels of development but decline steadily toward zero at higher levels of development. These findings offer a clear way to reconcile previous research showing that birth intervals are important for perinatal outcomes in low-income countries but are much less consequential in high-income settings.

Heterogeneous Effects of Birth Spacing on Neonatal Mortality Risks in Bangladesh.

The negative relationship between birth interval length and neonatal mortality risks is well documented, but heterogeneity in this relationship has been largely ignored. Using the Bangladesh Maternal Mortality and Health Care Survey 2010, this study investigates how the effect of birth interval length on neonatal mortality risks varies by maternal age at birth and maternal education. There is significant variation in the effect of interval length on neonatal mortality along these dimensions. Young mothers and those with little education, both of which make up a large share of the Bangladeshi population, can disproportionately benefit from longer intervals. Because these results were obtained from within-family models, they are not due to unobservable heterogeneity between mothers. Targeting women with these characteristics may lead to significant improvements in neonatal mortality rates, but there are significant challenges in reaching them.

Socio-economic status and fertility decline: Insights from historical transitions in Europe and North America.

The timings of historical fertility transitions in different regions are well understood by demographers, but much less is known regarding their specific features and causes. In the study reported in this paper, we used longitudinal micro-level data for five local populations in Europe and North America to analyse the relationship between socio-economic status and fertility during the fertility transition. Using comparable analytical models and class schemes for each population, we examined the changing socio-economic differences in marital fertility and related these to common theories on fertility behaviour. Our results do not provide support for the hypothesis of universally high fertility among the upper classes in pre-transitional society, but do support the idea that the upper classes acted as forerunners by reducing their fertility before other groups. Farmers and unskilled workers were the latest to start limiting their fertility. Apart from these similarities, patterns of class differences in fertility varied significantly between populations.