Compulsory face mask policies do not affect community mobility in Germany

There is currently a heated debate about whether the general public should be required to wear protective face masks to contain COVID-19. A key concern is that compulsory face mask policies will make the public feel safer, and may (due to risk compensation) undermine the most important public-health advice to contain COVID-19 – which is to reduce mobility and maintain social distancing. This study provides first evidence on the impact of compulsory face mask policies on community mobility. We use a difference-in-differences design, which exploits the staggered implementation of compulsory face mask policies by German states. We use anonymised GPS data from Google's Location History feature to measure daily mobility in public spaces. We find no evidence suggesting that compulsory face mask policies affect community mobility in public spaces in Germany. We can rule out even small increases in mobility that are larger than 0.03 standard deviations.