The depletion of forested wetlands is a pressing environmental concern, but has wetland depletion and conversion to agricultural cropland been excessive? A dynamic analysis of resource exploitation in the presence of environmental consequences is required. The structure and parameters of a model of socially optimal wetland use are found to bear a well-defined relationship to those which emerge from a private-market model of wetland exploitation, providing a basis for internalizing environmental externalities and for identifying optimal resource-exploitation strategies. Empirical analysis focuses on the area of severest wetland losses in the United States, the Lower Mississippi Alluvial Plain.
By affecting relative economic returns, public infrastructure investments can induce major changes in private land use. We find that 30 percent of forested wetland depletion in the Mississippi Valley has resulted from private decisions induced by federal flood-control projects, despite explicit federal policy to preserve wetlands. Our model aggregates individual land-use decisions using a parametric distribution of unobserved land quality; dynamic simulations are used to quantify the impacts on wetlands of federal projects and other factors.