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on Unemployment, Inequality and Poverty |
| By: | Jesús Fernández-Villaverde (University of Pennsylvania, NBER, and CEPR); Patrick Norrick (Northwestern University) |
| Abstract: | As of 2026, humanity is likely below replacement fertility. That has never happened before, not in wars or pandemics. But the real surprise is that the fall has been concentrated in low- and middle-income countries and among poorer and less educated women. We fit a single-factor model to 236 countries since 1950: the common component peaked in 1978, and what drives fertility down today are country-specific trends, 219 of them negative and not one leveling off. None of the commonly cited mechanisms can account for this pattern, so we offer a conjecture: modernity itself, which makes a third child expensive and childlessness cheap. Children come in integers, so it takes very little to move a cohort’s fertility rate from 1.8 to 1.3. And nothing in an economy pushes fertility back to 2.1. We close with the main economic consequences, in particular slow growth. |
| Keywords: | fertility decline; demographic transition; population aging; economic growth;labor force; population projections |
| JEL: | J11 J13 O40 E24 O11 |
| Date: | 2026–10–06 |
| URL: | https://d.repec.org/n?u=RePEc:pen:papers:26-016 |
| By: | Federico, Giovanni; Tena Junguito, Antonio |
| Abstract: | Humans have been migrating since the out-of-Africa dispersal, roughly 300, 000 years ago, but the nineteenth century marked a major leap forward. For the first time in history, millions of people voluntarily migrated over long distances, from Europe to the Americas and Oceania, and from India and China to Southeast Asia. Yet we still know too little about these flows. The recent literature has made great progress in analyzing migrants' motivations and the microeconomic impact of their arrival, but the conventional wisdom still relies on the data compiled by Ferenczi and Willcox (1929) on gross migrations in the Atlantic economy. In this paper, we reconstruct new worldwide series for total (gross) and net migration, including inter-Asian and, partially, inter-European flows from 1800 to 1938. We estimate that more than 150 million people, about 10% of the world population, migrated, but half of them returned home. They accounted for between a sixth and a tenth of the workforce in the Americas and from a fifth to three-quarters in Australia and New Zealand. We also estimate the long-run effect of migrations on the distribution of the world population. |
| Keywords: | International migration; Global migration; Historical demography; Return migration; Labor mobility; Population dynamics; Economic history |
| JEL: | J61 N30 J11 F22 |
| Date: | 2026–09–24 |
| URL: | https://d.repec.org/n?u=RePEc:cte:whrepe:50842 |
| By: | David Card; Jesse Rothstein; Moises Yi |
| Abstract: | We use data on 44, 000 twin pairs observed as adolescents in the 2000 Census, linked to their earnings 20 years later, to study the heritability of labor market outcomes. We extend the Classical Twins Design (CTD), which identifies heritability from contrasts between monozygotic and dizygotic twins, to settings where an analyst does not observe zygosity but can measure outcomes for same-sex and opposite-sex twins. We also allow for the presence of a family- and sex-specific component affecting same-sex siblings but only partly shared by opposite-sex siblings. Our extended model identifies heritability from the difference-in-differences of same-sex vs. opposite-sex twins vs. siblings. The estimates indicate strong heritability (h² approximately 0.36) of log earnings. Using an AKM (Abowd et al., 1999) decomposition that separates the person-specific component of earnings from employer-specific pay premiums, we find that both components are heritable. The heritability of employer pay premiums, however, is mainly driven by same-sex twins who work at the same firm, suggesting that social interactions may lead to an over-estimate of the genetic component in earnings. Excluding siblings who work together leads to estimates of the heritability of log earnings that are 15% lower. Similar biases may be present in CTD-based estimates of heritability for other social outcomes like education. |
| JEL: | C31 D31 J24 J31 J62 |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:nbr:nberwo:35746 |