Author Description

This paper summarizes highlights in the history of the ex-ante economic analysis of large dams. We argue that six key developments are especially important: 1) adding systems analysis; 2) incorporating multiple objectives; 3) introducing environmental and social gains and losses; 4) recognizing economy-wide linkages; 5) accounting for non-cooperative behavior; and 6) dealing with uncertainty. We conclude that current professional practice in the ex-ante assessment of large dams has not yet caught up with the scholarly literature on these six developments. After that discussion, we consider a small number of ex-post analyses of the economic effects of dams and discuss how their results align with what has been called for in ex-ante assessments.