Instream flow assessment and economic valuation: A survey of nonmarket benefits research

Instream flow benefits for United States streams and rivers have recently been investigated by a number of resource economists. These valuation efforts differ in scope, method, and quantitative results. An assessment and review of these valuation efforts is presented. The various sources of differences in nonmarket values produced by these studies are explored in some detail. The considerable difficulty of producing estimates of instream flow benefits values that consider all of the pertinent policy and technical issues is delineated in various policy contexts. Evidence is presented that indicates that the considerable policy impact of recent research on this topic is justified despite considerable variation in the magnitude of the estimates.