Estimating a socially optimal water price for irrigation versus an environmentally optimal water price through the use of Geographical Information Systems and Social Accounting Matrices

摘要

This article develops a method for establishing water prices and their effects in order to provide policy makers an environmentally and socially optimal range of regional prices for irrigation water. Two prices are determined. The "environmentally optimal price" of water is defined as the one that internalizes the environmental costs generated by agricultural consumption. The "social optimally price" of water is defined as the one that maximizes levies on water for agriculture without affecting the regional economy. The environmentally optimal price is calculated with an economic model built over a Geographical Information System (GIS) that allows the economic quantification and valuation of the environmental cost of water in different basins. The optimal price is calculated with a demand curve for irrigation water introduced into a Social Accounting Matrix (SAM) to observe if the regional economy can accept higher prices without affecting the regional GDP. Potential water prices are established, ranging from prices that minimize the negative impact in the regional economy to those that totally internalize the environmental cost of water.