Success on the Commons

The notorious `tragedy of the commons' is incorrectly held to be the eventual fate of all resources that are used collectively rather than by individual private owners. This essay reviews several examples around the world of successful collective management of environmental resources - institutional regimes that have operated for decades or even centuries without resulting in degradation of resources. It then explores the features shared by these historically unconnected institutional regimes in order to begin specifying the characteristics of regimes that circumvent tragedy. Successful systems usually have well defined communities of eligible user-managers and clear, easily enforced and environmentally cautious rules to constrain resource use. But they vary greatly in terms of the allocation of the harvested supply of the resource, from hierarchical systems of rights with unequal allocation of the resource to very egalitarian systems that assign equal shares by lottery.