Vaccines and Verdicts: How Smallpox Court Decisions Affect Anti-Vaccine Discourse and Mortality

We estimate the effect of compulsory vaccination court decisions on anti-vaccine discourse and mortality. We measure anti-vaccine discourse using language in American newspapers. Using human-classified training data and machine learning techniques, we predict anti-vaccine discourse for nearly 48,000 newspaper pages. Staggered difference-in-differences estimates show that anti-vaccine discourse increased for a period of two years after pro-vaccine state-level Supreme Court decisions before returning to baseline. Regression-discontinuity-in-time estimates yield similar findings following the Jacobson v. Massachusetts US Supreme Court decision. While compulsory vaccinations increase anti-vaccine discourse, mandates appear to remain effective, and we estimate that smallpox mortality rates fell in the wake of pro-vaccine decisions.