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...

A major provision of the Affordable Care Act was the creation of Health Insurance Marketplaces, which began operating for the 2014 plan year. Although enrollment initially grew in these markets, enrollment has fallen recently amid insurer exits and rising premiums. To better understand these...

A major provision of the Affordable Care Act was the creation of Health Insurance Marketplaces, which began operating for the 2014 plan year. Although enrollment initially grew in these markets, enrollment has fallen recently amid insurer exits and rising premiums. To better understand these...

Drug control policy can have unintended consequences by pushing existing users to alternative, possibly more dangerous substances. Policies that target only new users may therefore be especially promising. Using commercial insurance claims data, we provide the first evidence on a set of new...

The Affordable Care Act’s subsidies enable seven million Americans to purchase zero-premium insurance plans. Millions more are eligible for generously subsidized health plans with small, positive premiums. What difference does a premium of zero make, relative to a slightly positive premium?...

Drug control policy can have unintended consequences by pushing existing users to alternative, possibly more dangerous substances. Policies that target only new users may therefore be especially promising. Using commercial insurance claims data, we provide the first evidence on a set of new...