LAUSR

Most states enacted shelter-in-place orders (SIPOs) in mitigating the coronavirus disease 2019 (COVID-19) pandemic. Emerging evidence indicates SIPOs have reduced COVID-19 cases. Using data starting at different dates in March through May 15, 2020, we examine effects of SIPOs on daily growth rates of COVID-19 deaths and hospitalizations using event study models. We find that SIPOs reduced the daily mortality growth rate after nearly three weeks from enactment, and the daily growth rate of hospitalizations two weeks after enactment. After 42 days from enactment, the daily mortality growth rate declined by up to 6.1 percentage points. Projections suggest as many as 250,000-370,000 deaths possibly averted by May 15 in the 42 states plus the District of Columbia with statewide SIPOs. The daily hospitalization growth rate examined in 19 states with SIPOs and 3 states without SIPOs with data on hospitalizations has declined by up to 8.4 percentage points after 42 days. This evidence suggests that SIPOs have been effective in reducing the daily growth rates of COVID-19 deaths and hospitalizations. [Editor's Note: This Fast Track Ahead Of Print article is the accepted version of the peer-reviewed manuscript. The final edited version will appear in an upcoming issue of Health Affairs.].