Do Contingent Valuation Estimations Pass a 'Scope' Test?A Meta Analysis

This paper considers two tests proposed to judge the internal consistency of contingent valuation estimates. Both tests are quite sensitive to the maintained hypotheses required to derive fairly precise expectations for the properties of WTP functions. This result suggests a different approach may be needed in gauging the reliability of CV. This paper describes an alternative approach that relies on a weight of the evidence criterion and uses meta analysis to develop a systematic appraisal of what are the economic values of changes in amenity resources. The approach is illustrated for the case of estimating people's willingness to pay for improving (or maintaining) visibility at the national parks.