A TEST OF THE EQUALITY OF CLOSED-ENDED AND OPEN-ENDED CONTINGENT VALUATIONS

A test is developed to find whether open-ended and closed-ended contingent valuation mechanisms lead to significantly different results. The test is based on joint estimation of willingness to pay responses to open- and closed-ended questions asked of the same sample of individuals. In a public good example, individuals do respond differently depending on question format. Possible explanations include different incentives for strategic behavior and respondents' lack of familiarity with the open-ended question type. No differences in willingness to pay were found in a private good example.