Peer effects on influenza vaccination: Evidence from a city's administrative data in Japan

A characteristic that differentiates vaccination from other health behaviors is that it is a public good. By the nature of a public good, negative peer effects are expected when determining vaccination behavior for free-rider incentives. This study empirically analyzes whether the surrounding vaccination status in a community influences individual vaccination behavior using administrative data on influenza vaccination for all the older people within a city of Japan. We first employ fixed effect analysis with a lagged dependent variable. We then examine how vaccination behavior changes in the event of the loss of a cohabitant and how this effect interacts with the community peer effect. Our estimation results confirm positive peer effects: the higher the community's vaccination rate, the more the raising effect of the individual's vaccination rate.