On Dynamic Effects of the Number of Players in a Commons Game : A Tragedy of Nutria in Okayama

This paper considers a dynamic commons game in relation with mitigation of invasive alien species such as nutria in Okayama. In our commons game, players (trappers) non−cooperatively seek to maximize their own payoff by extracting the renewable resource stock (nutria). One key assumption is that the cost of extraction of the resource is negatively related to the current stock level. For a low level of resource stock, the extraction cost is high, which makes the extraction less lucrative for the players and which in turn stimulates the renewable resource stock to regenerate more rapidly. As the resource stock reaches a high level, the reverse process will start, and this can cause oscillating behaviors. Our simple model proposed here exemplifies that an increase in the number of players can drastically change the qualitative as well as quantitative features of the dynamics for the renewable resource stock.

研究ノート (Note)