We examine the impact of the free supply of diphtheria antitoxin, the first effective medical treatment for an infectious disease, on the historical health transition in Massachusetts. Using newly collected municipality-level data on the distribution of antitoxin and information from over 1.5 million death certificates from 1880 to 1914, we find that the rapid availability of antitoxin treatment significantly increased life expectancy at young ages. Our findings suggest that medicine, combined with an effective public health policy, played a more important role in improving life expectancy in the early twentieth century than previously thought. (JEL H75, I12, I18, J13, N31)
Ager et al. (2026) studied this question.