Vaccines influence the course of pandemics both directly, by protecting the vaccinated, and indirectly, by reducing transmission to the unvaccinated, a key externality. Estimating direct effects is challenging because of selective vaccine take-up; estimating indirect effects also poses...

"This paper tests whether income affects the body weight and clinical weight classification of elderly Americans using a natural experiment that led otherwise identical retirees to receive significantly different Social Security payments based on their year of birth. We exploit this natural...