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.
This paper documents an analysis of English demographic change over the period 1573–1873. A simultaneous equations model is developed in order to test four alternative demographic theories—the constant equilibrium wage theory, the constant fertility theory, Lee's original (1973) synthesis theory, and a new, composite theory. Each is a special case of a general demographic model which provides both for exogenous technological change and for endogenous migration behavior. Two-stage least-squares estimation yields parameter estimates and test statistics, which provide evidence of the superiority of the composite theory of demographic change. By statistically affirming the composite theory of demographic change, this paper confirms that the mortality level played a dominant role in English demographic change during the preindustrial period. The analysis also provides support, however, for the classical notion that shifts in the labor demand function were a dominant cause of long-run population changes, subsequent to the beginning of British industrialization.