Dynamics of forestry and agricultural land-use boundaries in Northeast Thailan

The process of land-use change in 11 villages in Northeast Thailand was examined using an economic model and survey observations of agents' agricultural activities. The economic model was based on the idea that agents make production decisions at points in the landscape with respect to the states of a reference point in space-time. Spatial discounting was defined to represent efficiency of factor inputs, where low and high discounting values represented high and low efficiency. The model was used to control the effects of natural spatial features on agents' production decisions in order to isolate economic effects on their decisions. The optimal solutions to the economic model articulate differences in production choices under efficient labor-use and efficient land-use criteria with respect to landlord profit.;Production functions for rice, corn, and kenaf were estimated, and used for simulation of unit-area-landlord profit and marginal productivity of factor inputs. The simulation results indicate lower unit-area-landlord profit in the 1990s compared to the 1980s, low unit-area-landlord profit resulting from the application of fertilizer, and low marginal productivity of labor input in high spatial discounting areas. Field observations reveal that land with low spatial discounting was preferred for agricultural production, that labor supply declined in the 1990s from the 1980s, and that a lower wage rate prevailed in high spatial discounting areas.;In the model framework employed, these simulation results and observations were consistent with the forestry and agricultural land-use boundaries moving into forestland in the 1980s, and into agricultural land in the 1990s. The former situation represents a conversion of forestland for agricultural use, and the latter represents a declining demand for agricultural land, and stabilization of the boundaries in the study area. The model interpretation also indicates that agriculture with low marginal productivity of labor consumes more forestland.;The simulation results and observations reflect economic growth initiated in the 1980s. The expansion of off-farm employment opportunities, aging, and out-migration motivated agents to begin to apply fertilizer and engage in mechanical ploughing, and decline of rice, corn, kenaf, and fertilizer real prices, and stable real wage rates influence the agents' production decisions.