We investigate the impact on mortality of the world's rst compulsory
health insurance, established by Otto von Bismarck, Chancellor of the
German Empire, in 1884. Multiple empirical approaches, based on international
comparisons and dierence-in-dierences strategies using Prussian
administrative panel data to exploit dierences in eligibility for insurance
across occupations, yield a consistent pattern suggesting that Bismarck's
Health Insurance generated a signicant mortality reduction. The
results are largely driven by a decline of deaths from infectious diseases.
We present prima facie evidence that diusion of new hygiene knowledge
through physicians was an important channel.