Working Papers

Circular Migration, Marriage Markets, and HIV: Long-Run Evidence from Mozambique [AEHN Working Paper 76, under review]

I study the impacts of exposure to one of Africa's largest circular migration flows using an arbitrary border within Mozambique that, from 1893 to 1942, separated areas where young men were either pushed into or prevented from migrating. Counterintuitively, but consistent with historical narratives and theoretical predictions, HIV prevalence is lower today on the former migrant-sending side of the border while living standards are similar. The evidence suggests that age gaps between partners – which promote HIV's spread – have long been smaller in this region, as circular migration allowed much younger men to afford the requisite marriage payments to brides' families.

Deworming as HIV Prevention for Young Women: Evidence from Zimbabwe

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 Control 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 Effects of the New Poor Law across Three Generations (with Jennifer Mayo)

We study the intergenerational impacts of cash transfers using the 1834 ("New") Poor Law, which drastically cut the income support that had been provided to 15 percent of the population in England and Wales and cost 2 percent of GDP. We show that in 1861, cohorts more exposed to income-support declines in childhood held lower-skilled jobs as adults and had fewer of their children in school. Linking these sons to the 1901 census, we find the same results for them as adults and for their children, highlighting the importance of accounting for multi-generational effects in cost-benefit analyses of social programs.

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