IDENTIFYING THE FREE RIDERS - A SIMPLE ALGORITHM FOR DETERMINING WHO WILL CONTRIBUTE TO A PUBLIC GOOD

When a heterogeneous group of people provide themselves with a pure public good the resulting Nash equilibrium outcome will divide the group into contributors and free riders. This paper proposes a general algorithm for discovering which individuals in the group fall into which of these two classes. The algorithm is based on identifying, for each individual, how much of the public good must be provided by others to drive that individual's contribution to zero.