Unhooking the past: Early-life exposure to hookworm eradication and later-life longevity

This study examines the long-term effects of the Rockefeller Sanitary Commission's (RSC) hookworm eradication campaign, initiated in the American South in the 1910s, on old-age longevity. Utilizing Social Security Administration death records linked to the 1940 full-count census, we employ a two-way fixed effect approach to examine the effects of early-life exposure to the eradication campaign on later-life outcomes. We find that individuals exposed to the RSC campaign during in-utero and early life experience an increase of approximately 1.3 months in longevity for a one-standard-deviation increase in county-level treatment intensity. The effects are substantially larger among nonwhites, children of illiterate mothers, and those born in urban areas. Moreover, we provide evidence of dynamic complementarity in the effects of hookworm eradication on longevity, with larger effects observed in counties exposed to the Rosenwald school construction movement and in states with more stringent child labor laws. Using the 1940 census and World War II enlistment data, we provide suggestive evidence of improvements in educational attainment, income, and cognitive ability as possible pathways. Our findings contribute to the literature on the lasting effects of early-life public health interventions and underscore the importance of such programs in addressing present-day global health challenges.