A Dictator Game Experiment with the COVID-19 Vaccinated and Unvaccinated People

Abstract

In this study, we conduct a dictator game experiment with the COVID-19 vaccinated and unvaccinated people in Japan (N=1,578), and ascertain allocation tendencies between two anonymous individuals, between two vaccinated individuals or two unvaccinated individuals, and between a vaccinated individual and an unvaccinated individual. By so doing, we assess “ingroup bias,” “outgroup bias,” and “ingroup-favoritism” of vaccinated and unvaccinated people, respectively. Here, ingroup bias is defined as the difference between the money amounts allocated to an individual of the same group as the allocator and to an anonymous individual in the dictator game experiment. Outgroup bias is defined as the difference between the money amounts allocated to an individual of a different group from the allocator’s and to an anonymous one, and ingroup-favoritism is defined as the difference between the money amounts allocated to an individual of the same group and to an individual of the different group. Our analyses find that vaccinated individuals have strong ingroup-favoritism and outgroup bias, while unvaccinated ones do not. We also find that the unvaccinated individuals have outgroup bias in the opposite direction of the hypothesis. This implies that they behave altruistically toward the vaccinated ones belonging to the outgroup. To stably manage a society under a pandemic, it is crucial to build cooperative relationships between vaccinated and unvaccinated people. This study can contribute to the smooth construction of such cooperative relationships.