Trade-off analysis of alternative water uses, by Roger B. Long

Professor Long's analysis is incorrect since it fails to distinguish between the gross value of agricultural production and the marginal net value of water used in irrigated agriculture. Long's analysis is valid only in the unlikely situation that all agricultural factors of production are in surplus except for water, all land is equally productive, all food and electricty prices are fixed with infinite demand, and the cost of irrigation development is zero. Since these conditions cannot exist, Long's trade-off analysis provides unsound advice to decision makers who must make critical water allocation decisions.