University of Louisville study finds mask mandates did not slow spread of COVID-19

Editor's Note

This study by researchers at the University of Louisville finds that state mask mandates did not help slow COVID-19 transmission.

The analysis compares COVID-19 case growth rates in 33 states that imposed statewide mask mandates on or before August 2, 2020, with states that imposed mask mandates after this date, and with states that didn’t have mask mandates at all.

The researchers found that case growth was not significantly different between mandate and non-mandate states at low or high transmission rates. In addition, differences between minimum and maximum case growth were similar among early, late, and no mandate states, and surges from minimum to maximum growth occurred at similar rates.

The data suggest that mask use is a poor predictor of COVID-19 growth at the state level, the researchers conclude. The findings do not support the hypothesis that COVID-19 transmission rates decrease with greater public mask use.