Interactive explainer Cutler, David, and Grant Miller (2005). Demography, 42(1): 1–22
Using the staggered arrival of filtration and chlorination in major US cities, the paper attributes roughly half of the 1900–1936 mortality decline to clean water.
Interactive explainer Almond, Douglas (2006). Journal of Political Economy, 114(4): 672–712
Cohorts in utero during the 1918 influenza pandemic had lower schooling, income and health decades later — the classic “fetal origins” natural experiment.
