In the absence of collective action, the use of the biosphere’s goods and services gives rise to an important class of reciprocal externalities. The externalities are most powerful when access to a resource base, which may be an entire ecosystem, is unrestricted. Today, the most prominent among open access resources are the atmosphere as a sink for gaseous and particle emissions, and the oceans beyond the 200-mile exclusive economic zones (EEZs) of nations.249 Anthropologists have discovered, however, that ecosystems with small geographical reach, such as village woodlands and ponds, are usually neither private property nor state property, but are instead communal property. In this chapter, we use the conceptual apparatus that was developed in Chapter 6 to provide a sense of the way communities in various parts of the world have tried to manage their local ecosystems. By so doing, we will gain an understanding of the successes and failures of societies to live within their local resource base.