Anomalies in contingent valuation, plausible empirical explanations

Resumo

Environmental valuation is an important analytical tool for policy decisions concerning the environment. The Contingent Valuation (CV) method is a widely employed tool for assessing non use values of natural resources. The method is however subject to critics concerning anomalies. The most important anomaly is insensitivity to scope. As a consequence, a great effort has been made in the literature for explaining this controversy. Based on this extensive work, I provide new alternative explanations not previously explored that help us understanding motives causing insensitivity to scope. With this aim, empirical approaches which explore determining reasons for insensitivity to scope are conducted here. A meta-analysis on willingness to pay estimates for wildlife and ecosystem goods provides evidence of the effect information about the amount of the good has in sensitivity to scope. Moreover, use and non use values are not valued the same way. Thee case studies concerning a high use value species and a high non use value species are conducted where high use values species are sensitive to scope. Additionally, other factors such as the uniqueness of the good, ethical motivations, respondent"s roles or the expected values associated to a recovery level are seen to affect scope test results.