Typhoid Fever, Water Quality, and Human Capital Formation

Investment in water purification technologies led to large mortality declines by helping eradicate typhoid fever and other waterborne diseases. This paper seeks to understand how these technologies affected human capital formation. We use typhoid fatality rates during early life as a proxy for water quality. To carry out the analysis, city-level data are merged with a unique dataset linking individuals between the 1900 and 1940 censuses. Parametric and semi-parametric estimates suggest that eradicating early-life exposure to typhoid fever would have increased earnings in later life by 1% and increased educational attainment by one month. Instrumenting for typhoid fever using the typhoid rates from cities that lie upstream produces similar results. A simple cost-benefit analysis indicates that the increase in earnings from eradicating typhoid fever was more than sufficient to offset the costs of eradication.