Strategy-proofness in Environmental Valuation: Some Positive Results

One of the most widely appreciated problems of contingent valuation is the potential manipulability of the method, thus subjecting it to possible strategic bias. This paper shows that under usual conditions this problem also holds for market-based methods, such as travel cost and hedonic pricing. However, not all formats of these valuation methods are manipulable. This paper finds positive results for the contingent valuation method when some conditions are met. In particular it proposes a social choice framework where the open-ended median elicitation format of the contingent valuation method is strategy-proof.