How Do Respondents with Uncertain Willingness to Pay Answer Contingent Valuation Questions?
通过分样本条件价值评估研究，比较四种诱导方法，发现支付卡法给出的支付意愿低于二分选择法，但二分选择法受访者更不确定；当要求“几乎确定”时，两种方法结果趋同。
<i>Four elicitation methods are compared in a split-sample, contingent-valuation study valuing avoidance of episodes of ill health linked to air pollution: two discrete methods and two more-continuous methods. Respondents to a traditional payment card (PC) question gave willingness-to-pay values that were lower than those implied by dichotomous-choice (DC) responses. However, follow up questions showed that DC respondents were less certain of their stated behavior than were PC respondents. When respondents were told to be “almost certain” of their responses, responses to the DC and the PC formats converged.</i>