We use a public good game with rewards, played on a dynamic network, to illustrate how
self-organizing communities can achieve the provision of a public good without a central authority
or privatization. Given that rewards are given to contributors and that the choice
of whom to reward depends on social distance, free-riders will be excluded from rewards
and the (almost efficient) provision of a public good becomes possible. We review the related
experimental economics literature and illustrate how the model can be tested in the
laboratory.
