Eficiencia de las reglas de asignación de agua en el regadío: asignación a través de mercados, de la regla proporcional y de la regla uniforme

In this paper, the introduction of three different methods for the assignment of water in agriculture is simulated in order to compare its economic efficiency for the case of an irrigated area located in the central Ebro Valley. Apart from the currently applied proportional system, water markets have been simulated along with the uniform rule, developed in social choice theory. The results show that although the water market achieves the best results in all cases, the uniform rule can be an interesting alternative to current management methods if water assignments are at regular levels, while in the case of severe water shortage; markets offer a clearer advantage with regard to any other method. The results also show that higher levels of heterogeneity between firms and high water prices situate the uniform rule in a more favorable situation then the currently applied proportional system.