Contingent valuation and actual payment for voluntarily provided passive-use values: Assessing the effect of an induced truth-telling mechanism and elicitation formats

A fundamental question about the contingent valuation (CV) method is to what degree it predicts actual payments (AP). This has particularly been an intriguing matter related to voluntary provision of public goods representing primarily passive-use values. This paper reports the results from such a CV–AP comparison. Applying a voluntary payment mechanism there exists a theoretical expectation of upward bias in CV estimates and downward bias in AP. This study applied an induced truth-telling mechanism in one treatment group to assess the hypothetical bias effect in CV. The CV estimates in this treatment group were significantly lower than in the group that did not face this mechanism. But this effect was limited to those responding/acting to dichotomous choice, not affecting those responding to open-ended questions about willingness to pay.