Vaccination and Risk Aversion: Evidence From a Flu Vaccination Campaign

We examine the causal effect of a French flu vaccination campaign on vaccination behavior. Individuals aged 65 and over receive an invitation letter with a voucher for a free flu shot, while those who are not eligible have to cover the costs themselves. Using a Fuzzy Regression Discontinuity Design, we find that receiving the invitation letter with the voucher leads to a significant increase in the likelihood of getting vaccinated. This effect is driven by individuals who are risk-averse. As illustrated in our theoretical model, for them, the costs of influenza infection outweigh the costs of the vaccine's side effects.