疫苗接种意向的情境依赖：对新冠病毒疫苗的支付意愿特征及其政策含义

We examine vaccination intention of elderly people in Japan by conducting an original survey in January 2021 and using the response data of hypothetical questions in the survey to capture willingness-to-pay (WTP) for the COVID-19 vaccine. The main findings are as follows. First, we find that the WTP of the elderly respondents varies depending on situations, including the infection level in the population and the progress of the vaccination program. On the other hand, many of them intend to be vaccinated when the vaccine is provided free of charge. For all scenarios, 71.1% to 80.9% of them answered that they would be willing to receive the vaccine if it were free of charge. We also find that those with stronger vaccination intention are more likely to take infection preventive measures, but also have more opportunities to come into contact with other people. No observed results suggest that the vaccination intention increases when subjects receive messages emphasizing the selfish or altruistic benefits of vaccination in addition to explanations on an objective of the vaccination. Based on this analysis and other research in behavioral economics, we derive and discuss policy implications for the development of a plan to promote voluntary vaccination.