Influenza vaccination could be a cost-effective way to reduce costs in terms of human lives and productivity losses, but low take-up rates and vaccination unintentionally causing moral hazard may decrease its benefits. We ran a natural field experiment in cooperation with a bank in Ecuador,...

We analyze the effects of a vaccination program providing free flu vaccine to individuals aged 65 or more on take-up behavior and hospitalization. Using both administrative and survey data, we implement a regression discontinuity design around the threshold at age 65, and find that the effect of...