Competition versus optimal control in groundwater pumping

This article considers one of the most important issues in water resources research, namely, the management of groundwater. Economists have long taken it for granted that the temporal allocation of groundwater would lead to welfare losses if left to the free market because all farmers pump from a common aquifer. Hence water economists studied extensively optimal control of temporal groundwater allocation. They never paused to compare the temporal allocation yielded by optimal control with the free market. In this article we prove by comparing the two strategies analytically that if the storage capacity of the aquifer is relatively large, the difference between them is so small that it can be ignored for practical consideration.