We study policy instruments to correct inefficiently low investment in maternal nutrition in India, where one-fifth of all births occur.

The size of the human population is projected to peak in the 21st century. But quantitative projections past 2100 are rare, and none quantify the possibility of a rebound from low fertility to replacement-level fertility. Here we provide updated long-term cohort-component population projections and extend the set of scenarios in the literature to include scenarios in which future fertility (a) stays below replacement or (b) recovers and increases.

Although fertility in India has declined to levels similar to HICs, women’s entry into marriage and initiation of childbearing are more in line with patterns found in LMICs.

Presented at National Bureau of Economic Research 2023 Fertility Conference; this paper subsumes “A Quantitative Assessment of the Climate Benefits and Economic Costs of a Smaller World Population.”

Tools are needed to benchmark carbon emissions and pledges against criteria of equity and fairness. Here we propose a utilitarian benchmark computed in a transparent optimization framework, which could usefully inform the equity benchmark debate.

In this paper, we review evidence from population science, in order to inform debates in population ethics that, so far, have largely taken place within the academic philosophy literature.

Utilitarianism is the most prominent family of social welfare functions. We present three new axiomatic characterizations of utilitarian (that is, additively separable) social welfare functions in a setting where there is risk over both population size and the welfares of individuals.

Grill (2023) defends the sum of averages view (SAV), on which the value of a population is found by summing the average welfare of each generation or birth cohort. A major advantage of SAV, according to Grill, is that it escapes the Egyptology objection to average utilitarianism. But, we argue, SAV escapes only the most literal understanding of this objection, since it still allows the value of adding a life to depend on facts about other, intuitively irrelevant lives.

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.

The United States Supreme Court’s ruling in Dobbs v. Jackson Women’s Health Organization has made understanding the impact of abortion laws increasingly important and timely. We investigate recent claims by policymakers that abortion restrictions increase birth rates; we also evaluate consequences for human capital and women’s welfare.

Pritchett (1994) influentially examined the relationship between survey-reported ideal fertility and period total fertility rates. Pritchett’s analyses found that country-period by country-period differences in fertility preferences could statistically account for the majority of the variation in period total fertility rates. This result was impactful because it suggested that preferences, rather than constraints such as contraceptive access, explain fertility outcomes.

We study policy instruments to correct inefficiently low investment in maternal nutrition in India, where one-fifth of all births occur.

A growing literature indicates that effects of early-life health on adult economic outcomes could be substantial in developing countries, but the magnitude of this effect is debated. We document a robust gradient between the early-life mortality environment to which men in India were locally exposed in their district and year of birth and the wages that they earn as adults.

The population ethics literature has long focused on attempts to avoid the repugnant conclusion. We show that a large set of social orderings that are conventionally understood to escape the repugnant conclusion do not in fact avoid it in all instances.

The Repugnant Conclusion served an important purpose in catalyzing and inspiring the pioneering stage of population ethics research. We believe, however, that the Repugnant Conclusion now receives too much focus. Avoiding the Repugnant Conclusion should no longer be the central goal driving population ethics research, despite its importance to the fundamental accomplishments of the existing literature.