Economics of agricultural water use at different scales.

Summary This thesis is a contribution to the analysis of agricultural water scarcity in temperate climates. It proposes resource allocation models from the plot to the regional scale. The empirical applications are based on the coupling of economic and agronomic models. The first chapter is a review of existing water policies. The second chapter presents the conditions under which the water demand function is identifiable. The third chapter studies the impact of a temporary ban on irrigation on the water demand function: this device may induce a higher annual consumption of the resource than in an unregulated situation. The fourth chapter considers the problem of sharing a scarce water resource between heterogeneous farmers facing climatic risk. It is shown that second-order allocation rules affect individual profits without significantly modifying the aggregate surplus.