The Effect of Temperature on Covid-19 Confirmed Cases: Evidence from US Counties

This paper studies the effect of air temperature on the transmission of COVID-19 in the U.S. using daily observations across counties. This study uses various ordinary least squares (OLS) models with a comprehensive set of fixed effects to overcome unobserved heterogeneity issues across counties as well as the generalized method of moments (GMM) estimators as dynamic models to address endogeneity issue. Our main results indicate that an increase of one degree in temperature is associated with a reduction of 0.041 cases per 100,000 population at the county-level. We run several robustness tests and all the models confirm the impact of temperature on COVID-19 confirmed new cases. These results help policymakers and economists in optimizing decisions and investments to reduce COVID- 19 new cases.