How Sensitive Are Environmental Values to Payment Card Design in Contingent Valuation?

Abstract

Contingent valuation studies of people’s willingness to pay (WTP) for ecosystem services are frequently used to inform the social benefit-cost analysis of environmental protection measures. Though contingent valuation is generally accepted in this context, response anomalies exist. Drawing on the anchoring-and-adjustment heuristic in psychology and context effects literature, we examine the impact of subtle design variation on people’s WTP. In a split-sample national survey of WTP to prevent coastal environmental damages from oil spills, different payment card elicitation formats significantly affect mean WTP, at most by 43%. This underscores the importance of a research agenda on the effects of subtle design variation on environmental value estimates.