Evolutionary game analysis of rural rebuilding: The synergy of social innovators and cooperators

Since the tragedy of the commons, the commons management has been recognized as a social dilemma. Moreover, not only has the free-rider problem been discussed, but the possibility of self-governance among participants has also emerged as one of the major concerns. In recent years however, the commons management in Japan is confronted with another problem that residents in rural areas abandon their commons due to the progress of depopulation and aging. In this paper, we focus on the role of social innovators who will contribute to regional development and a joint-venture between social innovators and cooperators to utilize regional resources. First, we formulate the situation where the free rider problem and the depopulation occur by the loner strategy in the optional public goods game. Second, we incorporate the social innovators in our model, and analyze how the joint-venture can resolve the commons problems. Our model shows the following: (i) Regardless of its profitability, the joint-venture between the majority of the cooperators and the minority of the social innovators can maintain the commons, (ii) Increasing subsidies for the residents in rural areas generates migrations of the social innovators, but it makes them become the free riders in the area. As a result, the tragedy of the commons is repeated.