Do Trump rallies spread COVID-19?
It looks like the answer is yes.
It's been a while, but I'm back, and with a new paper with Doug Bernheim, Nina Buchmann, and Seba Otero:
We investigate the effects of large group meetings on the spread of COVID-19 by studying the impact of eighteen Trump campaign rallies. To capture the effects of subsequent contagion within the pertinent communities, our analysis encompasses up to ten post-rally weeks for each event. Our method is based on a collection of regression models, one for each event, that capture the relationships between post-event outcomes and pre-event characteristics, including demographics and the trajectory of COVID-19 cases, in similar counties. We explore a total of 24 procedures for identifying sets of matched counties. For the vast majority of these variants, our estimate of the average treatment effect across the eighteen events implies that they increased subsequent confirmed cases of COVID-19 by more than 250 per 100,000 residents. Extrapolating this figure to the entire sample, we conclude that these eighteen rallies ultimately resulted in more than 30,000 incremental confirmed cases of COVID-19. Applying county-specific post-event death rates, we conclude that the rallies likely led to more than 700 deaths (not necessarily among attendees).
Update: Here is an event study graph shared by my co-author:
Here is the ES with county & week x state FEs & time-varying restrictions (masks & shelter-in-place), showing coefficients from -5 to +4 (so all coeffs. are based on the same set of event counties). There is no effect in the weeks before but builds up significantly after. (3/N) pic.twitter.com/iqR1uzcHVb— Nina Buchmann (@NinaBuchmann6) November 3, 2020