This book is the first attempt to analyze vaccination, which is a voluntary provision of public goods, from both empirical and theoretical perspectives, considering the possibility of a positive peer effect rather than a negative peer effect. From an economic perspective, vaccination has the benefits of reducing the probability of infection or disease onset not only for the individual but also for others in the surrounding area. The benefits are non-excludable and non-rivalrous, and have a public good character. The traditional theoretical framework for public goods predicts a free ride for the surrounding persons (i.e. negative peer effects) However, actual vaccination data do not necessarily support results in line with traditional theory. We empirically examine whether a positive peer effect exists with regard to influenza vaccination among the older adults in Japan, and find positive peer effects. Furthermore, based on the framework of the voluntary provision of public goods, we provide a theoretical model which is consistent with the positive peer effect. A positive peer effect can be derived as a Nash equilibrium of a two-person economy with simultaneous moves. Furthermore, under certain conditions, a positive peer effect also exists as a Nash equilibrium in a sequential move game. These theoretical findings have not been obtained in previous studies. 

Naomi Miyazato is Professor of College of Economics, Nihon University, and Visiting Scholar of the Research Institute of Capital Formation, Development Bank of Japan. He specializes in Public Finance, Social Security, Empirical Economics. He is a member of the board of directors of the Japan Institute of Public Finance, and is an author of The Political Economy of Population Aging: Japan and the United States, Springer (September 2021). He holds a Ph.D. in Economics from the University of Tokyo.

Jun-ichi Itaya is Professor of the Department of Human and Social Sciences, Faculty of Future Design, Hokkaido University of Science. He specializes in Public Economic, Economic Growth Theory, and Game Theory. He has served as a delegate to the Japanese Economic Association, and published many papers in leading journals, such as the Journal of Public Economics, International Tax and Public Finance, and the Journal of Population Economics. He holds a Ph.D. in Economics from the University of Rochester.