Research Note: Intergenerational Transmission Is Not Sufficient for Positive Long-Term Population Growth.

All leading long-term global population projections agree on continuing fertility decline, resulting in a rate of population size growth that will continue to decline toward zero and would eventually turn negative. However, scholarly and popular arguments have suggested that because fertility transmits intergenerationally (i.e., higher fertility parents tend to have higher fertility children) and is heterogeneous within a population, long-term population growth must eventually be positive, as high-fertility groups come to dominate the population. In this research note, we show that intergenerational transmission of fertility is not sufficient for positive long-term population growth, for empirical and theoretical reasons. First, because transmission is imperfect, the combination of transmission rates and fertility rates may be quantitatively insufficient for long-term population growth: higher fertility parents may nevertheless produce too few children who retain higher fertility preferences. Second, today even higher fertility subpopulations show declining fertility rates, which may eventually fall below replacement (and in some populations already are). Therefore, although different models of fertility transmission across generations reach different conclusions, depopulation is likely under any model if, in the future, even higher fertility subpopulations prefer and achieve below-replacement fertility. These results highlight the plausibility of long-term global depopulation and the importance of understanding the possible consequences of depopulation.

The Consequences of Social Inequality for the Health and Development of India's Children: The Case of Caste, Sanitation, and Child Height.

The links among social inequality, economic inequality, and health have long been of interest to social scientists, but causal links are difficult to investigate empirically. In particular, studies examining the impact of social status on one's own health may overlook important effects of inequality on the health of populations as a whole occurring due to negative externalities of social forces. A recent literature on caste, sanitation, and child net nutrition provides an example of one social context where social inequality makes an entire population less healthy. This paper presents new observational analysis of the India Human Development Survey that provides descriptive evidence of this mechanism. We show that, on average, children in rural India are shorter if they live in villages where more people report practicing untouchability-meaning that they enforce caste hierarchies in their interactions with people from the lowest castes. This association is explained by the association between casteism and the prevalence of rural open defecation.