Risk aversion and mobility in the public goods game

Abstract

In this paper, we study the evolutionary dynamics of the public goods game where the population of mobile individuals is divided into separate groups. We extend the usual discrete strategy game, by introducing "conditional investors" who have a real-value genetic trait that determines their level of risk aversion, or willingness to invest into the common pool. At the end of each round of the game, each individual has an opportunity to (a) update their risk aversion trait using a form of imitation from within their current group, and (b) to switch groups if they are not satisfied with their payoff in their current group. Detailed simulation experiments show that investment levels can be maintained within groups. The mean value of the risk aversion trait is significantly lower in smaller groups and is correlated with the underlying migration mode. In the conditional migration scenarios, levels of investment consistent with risk aversion emerge.