The Spread of Free-Riding Behavior in a Social Network

We propose a model where agents located in a social network decide whether or not to exert effort to provide a local public good. We assume that they have strong incentives to free-ride on their neighbors’ effort decisions. We characterize the equilibria of the induced game. We also study a mean-field dynamics in which agents choose in each period the best response to the last period's decisions of their neighbors. We characterize the fraction of free-riders in the stable state of such a dynamics and show how it depends on properties of the degree distribution.