Mask mandates and covid-19 related symptoms in the us

Purpose: This study investigates the extent to which the Public Mask Mandate, a policy that requires the use of face masks in public, can protect people from developing COVID-19 symptoms during the initial stage of the pandemic from mid-April to early June 2020 in the United States (US). Methods: We employ the difference-in-differences model that exploits the differential timing of the mask mandate implementation across states. Results: Our findings show that the Public Mask Mandate significantly lowers the incidence of developing all COVID-19 symptoms by 0.29 percentage points. The estimate implies an average reduction of 290%, compared to the proportion of the mandate-unaffected indivi-duals who display all symptoms (0.1%). Conclusion: The study provides suggestive evidence for the health benefits of wearing masks in public in the initial stage of the COVID-19 pandemic. The study also highlights the relevance of public mask wearing for the ongoing pandemic where the vaccination rate is precarious and access to vaccines is still limited in many countries. � 2021 Nguyen.