We exploit recent molecular genetics evidence on the genetic basis of arsenic excretion and unique information on family links among respondents living in different environments from a large panel survey to uncover the hidden costs of arsenic poisoning in Bangladesh. We provide for the first time estimates of the effects of the ingestion and retention of inorganic arsenic on direct measures of cognitive and physical capabilities as well as on the schooling attainment, occupational structure, entrepreneurship, and incomes of the rural Bangladesh population. We also provide new estimates of the effects of the consumption of foods grown and cooked in arsenic-contaminated water on individual arsenic concentrations. The estimates are based on arsenic biomarkers obtained from a sample of members of rural households in Bangladesh who are participants in a long-term panel survey following respondents and their coresident household members over a period of 26 years.

We examine empirically the generalizability of internally valid micro-estimates of causal effects in a fixed population over time when that population is subject to aggregate shocks. Using panel data, we show that the returns to investments in agriculture in India and Ghana, small and medium non-farm enterprises in Sri Lanka, and schooling in Indonesia fluctuate significantly across time periods. We show how the returns to these investments interact with specific, measurable, and economically relevant aggregate shocks, focusing on rainfall and price fluctuations. We also obtain lower-bound estimates of confidence intervals of the returns based on estimates of the parameters of the distributions of rainfall shocks in our two agricultural samples. We find that even these lower-bound confidence intervals are substantially wider than those based solely on sampling error that are commonly provided in studies, most of which are based on single-year samples. We also find that cross-sectional variation in rainfall cannot be confidently used to replicate within-population rainfall variability. Based on our findings, we discuss methods for incorporating information on external shocks into evaluations of the returns to policy.

In this paper, we address the issues of whether reductions in fertility increase human capital investments per child and whether twinning can identify the quantity—quality (Q-Q) trade-off. We show that estimates of the effects of twinning at higher parities on the outcomes of older children in prior studies do not identify family-size effects but are confounded by inter-child allocation effects because of the endowment deficit and close spacing of twins. However, examining the effects of twinning by birth order, net of the effects stemming from the endowment deficit of twins, can provide upper and lower bounds on the trade-off between the family size and average child quality. Our estimates, based on data from China, indicate that an extra child at parity one or at parity two, net of one component of birth-endowment effects associated with birth weight, significantly decreases the schooling progress, the expected college enrolment, grades in school and the assessed health of all children in the family. Despite the evident significant trade-off between number of children and child quality in China, the findings suggest that the contribution of the one-child policy in China to the development of its human capital was modest.

Andrew D. Foster, Mark R. Rosenzweig; Household Division and Rural Economic Growth, The Review of Economic Studies, Volume 69, Issue 4, 1 October 2002, Pages 83

We use data from an agricultural labour market in which workers receive both time- and piece-rate wages and shift frequently among employers and tasks, to assess the roles of comparative advantage, information problems and preferences in determining the allocation of workers. The estimates which impose minimal structure not implied by economic theory are consistent with a one-factor productivity model, and indicate that information asymmetries are present but workers are sorted according to comparative advantage. In particular, the disproportionate presence of female workers in weeding activities is due not to worker or employer preferences but to comparative advantage and statistical discrimination.