Public investment on health and voter responses: Evidence from the mass vaccination during COVID-19

This study examines the effect of COVID-19 vaccination on political support by leveraging Japan’s age-based vaccination rollout, which prioritized people aged 65 and older. Using a fuzzy regression discontinuity design, we found that vaccination increased favorable opinions of vaccination progress and infection control measures by 27.4% and 14.7%, respectively. These favorable opinions extended to positive perceptions of other infection control measures, ultimately fostering trust in the government. In addition, the effect of vaccination was heterogeneous: it was more pronounced among individuals with chronic diseases, women, those of lower socioeconomic status, and those with higher levels of interpersonal trust. In contrast, low trusters became more dissatisfied with how the Tokyo Olympics and Paralympics in 2021 were managed, without showing an increase in positive opinions of the government.