School closures, youth driving restrictions, and COVID-19 transmission

School closures were the first and most rapidly implemented major social distancing measures (SDMs) to prevent COVID-19 transmission in spring 2020. Their effectiveness, however, likely varied by local factors affecting youth off-campus mobility and peer interactions. Our study examines state Graduated Driver Licensing (GDL) programmes, which regulate youth driving by limiting the number of youth passengers and/or night-time driving hours, thereby reducing off-campus mobility and discouraging peer socialization, which could enhance the social distancing effects of school closures in COVID-19 prevention among teenagers, their families, and the broader population. Using a difference-in-differences framework, we exploit the exogenous 'policy shock' to GDL youth driving restrictions when the spring 2020 school closures began and peer socialization transitioned off-campus. We find that reducing youth passengers allowed led to lower county-level COVID-19 incidences among all-age populations during school closures. The effects are stronger with higher population density, longer gaps from school closures to lockdowns, and higher state minimum full driver licensure ages. Our findings complement the existing literature on intentional SDMs, support the evidence of intergenerational COVID-19 transmission, suggest beneficial 'spillover' effects of age-targeted public health policies, and emphasize the importance of considering local contexts when developing public policies like SDMs during pandemic emergencies.