Over the last two centuries, many millions of Africans have engaged in circular migration. I study its long-run impacts on their home regions using an arbitrary border within Mozambique that, from 1893 to 1942, separated areas where colonial authorities either incentivized or restricted young men’s migration. Consistent with narrative evidence and a model, HIV prevalence is lower today on the former migration-incentivizing side while living standards are equivalent. This health disparity likely arose from partner age gaps – which promote HIV’s spread – having long been smaller on that side, as circular migration enabled young men in bride price societies to marry.
Nearly one-third of new HIV infections in Sub-Saharan Africa occur in young women, largely because their partners are from high-prevalence groups. Since marriage market matching is shaped by human capital, which is influenced by childhood health, can deworming girls lower their chances of contracting HIV as young women? To answer this question, I study Zimbabwe’s school-based deworming program (2012-17), which substantially reduced rates of urogenital schistosomiasis. Using a difference-in-differences design, I find that 3 years after it began, young women’s HIV prevalence fell 2.7 percentage points (p.p., 44 percent) more in high-schistosomiasis districts. Human capital’s effects on marriage market matching appear to explain the results: young women’s secondary school attendance rose 6.0 p.p. (9 percent), and they had less age-disparate and fewer sexual partners. These results show that a cheap treatment for a common childhood disease can also slow an expensive and deadly pandemic, substantially increasing deworming’s estimated benefits.
Work in Progress
Disease, Disparities, and Development: Evidence from Chagas Disease in Brazil (with Eduardo Montero)
Neglected tropical diseases (NTDs) primarily afflict the poorest people in developing economies and often lead to chronic health issues. Combating them could thus reduce inequality and burdens on healthcare systems in these countries. We show that such novel benefits of disease control indeed arose from Brazil's initial campaign to eliminate Chagas disease (1984-89), which occurs almost entirely among poor, non-white, and rural Latin Americans and can cause long-run heart problems. Exploiting the pre-treatment presence of its main vector, we find that having a childhood free of exposure to this NTD raised non-white Brazilians' incomes by more than twice as much as their white peers' (7.7 vs 3.4 percent), and it decreased the interquartile range of incomes by 3.3 percent. We also estimate that, coinciding with the expected reduction in chronic Chagas disease symptoms, public spending on circulatory disease hospital care declined by 13.5 percent (0.014 percent of 2019 GDP), yielding by itself an internal rate of return of 24.9 percent. These results suggest that NTD control can reduce (racial) disparities in one of the world's most unequal regions while improving the public and fiscal health of developing countries.
Rags to Rags: The Intergenerational Effects of the 1834 Poor Law (with Jennifer Mayo)
Health as Structural Transformation: Evidence from Guinea Worm Disease Eradication in Ghana (with Conor Carney)
Blood Taxes: The Development Effects of Military Conscription in Colonial French West Africa (with James Allen IV)
Data collection in progress at the Archives Nationales du Sénégal, Dakar, Senegal
The Promises and Pitfalls of Using DHS Data for Comparisons across Countries and National Borders