The relationship between in-person voting and COVID-19: Evidence from the Wisconsin primary.

On April 7, 2020, Wisconsin held its presidential primary election, and news reports showed long lines of voters due to fewer polling locations. We use county-level variation in voting patterns and weekly county-level COVID test data to examine whether in-person voting increased COVID-19 cases. We find a statistically significant association between in-person voting density and the spread of COVID-19 2-3 weeks after the election. In our main results, a 10% increase in in-person voters per polling location is associated with an 18.4% increase in the COVID-19 positive test rate 2-3 weeks later.