The Structure of Uncultivated Wilderness: Land Use Beyond the Extensive Margin

This paper presents an agent-based model of shifting cultivation that explains patterns of land use and forest structure beyond the extensive margin of agriculture. The anthropological literature is first examined in order to specify key aspects of farming group preferences vis-a-vis food requirements. Two existing theories of shifting cultivation are then addressed to motivate the present formulation, which integrates household production theory and the concept of optimal rotation originating in the forestry literature. It is argued that the cycling of secondary vegetation by shifting cultivators represents a form of rotation analogous to the foresters' case. The model developed explains the empirical observation that individual agents use multiple rotation ages, and it does so for the nonmarket case, which is consistent with the institutional environment of many indigenous peoples and colonists. The paper concludes with an application to the problem of rural violence in Brazil and with suggestions for extending the framework to the policy arena of global change.