Would the affected communities voluntarily obtain herd immunity if a cure for COVID-19 was available? This paper experimentally investigates people’s vaccination choices in the context of a nonlinear public good game. A “vaccination game” is defined in which costly commitments (vaccination) are required of a fraction of the population to reach the critical level needed for herd immunity, without which defectors are punished by the natural contagion of epidemics. Our experimental implementation of a vaccination game in a controlled laboratory setting reveals that endogenous epidemic punishment is a credible threat, resulting in voluntary vaccination to obtain herd immunity, for which the orthodox principle of positive externalities fails to account. The concave nature of the infection probability plays a key role in facilitating the elimination of an epidemic.
【초록키워드】 COVID-19, vaccination, Immunity, Infection, Epidemics, Laboratory, Probability, Epidemic, implementation, Community, Critical, Contagion, fraction, positive, defined, resulting, affected, required, costly, reveal, 【제목키워드】 vaccination, herd immunity,