Theory, data, methods: developing spatially explicit economic models of land use change

Questions of land use/land cover change have attracted interest among a wide variety of researchers concerned with modeling the spatial and temporal patterns of land conversion and understanding the causes and consequences of these changes. Among these, geographers and natural scientists have taken the lead in developing spatially explicit models of land use change at highly disaggregate scales (i.e. individual land parcels or cells of the landscape). However, less attention has been given in the development of these models to understanding the economic process - namely, the human behavioral component that underlies land use change. To the extent that researchers are interested in explaining the causal relationships between individual choices and land use change outcomes, more fully articulated economic models of land use change are necessary. This paper reviews some of the advances that have been made by geographers and natural scientists in developing these models of spatial land use change, focusing on their modeling of the economic process associated with land use change. From this vantage point, it is argued that these models are primarily "ad hoc," developed without an economic theoretical framework, and therefore are susceptible to certain conceptual and estimation problems. Next, a brief review of traditional economic models of land use determination is given. Although these models are developed within a rigorous economic framework, they are of limited use in developing spatially disaggregate and explicit models of land use change. Recent contributions from economists to the development of spatially explicit models are then discussed, in which an economic structural model of the land use decision is developed within a spatially explicit framework and from which an estimable model of land use change is derived. The advantages of this approach in terms of simulating policy scenarios and addressing econometric issues of spatial dependency and endogeneity are discussed. We use some specific examples from ongoing research in the Patuxent Watershed, Maryland, USA. to illustrate our points. The paper concludes with some summary remarks and suggestions for further research. (C) 2001 Elsevier Science B.V. All rights reserved.