Do Masks Protect Children? Evidence from Florida’s Mask Mandate Ban Using Large-Scale School Transmission Data

Abstract

Our study examines the causal impact of mask mandates on COVID-19 transmission in elementary and middle schools using a natural experiment in Florida. While randomized controlled trials (RCTs) have been the gold standard for causal investigation, they face challenges such as lower compliance rates and typically focus only on the direct impact on mask wearers, overlooking the potential benefits of transmission reduction. Our natural experiment overcomes these issues, providing a broader view of mask mandates’ effects. The results show a 20.6% increase in COVID-19 cases when mask mandates are banned. We also explore the moderating effects of school size, search volume for “mask,” and racial and poverty groups on the impact of the mask ban. Our study underscores the critical role of mask mandates and showcases the potential of utilizing publicly accessible data to generate insights on significant societal issues – a principle at the core of crowd-based platforms.