Mitigating hypothetical bias : evidence on the effects of correctives from a large field study

The overestimation of willingness-to-pay (WTP) in hypothetical responses is a wellknown finding in the literature. Various techniques have been proposed to remove or, at least, reduce this bias. Using responses from a panel of about 6,500 German households on their WTP for a variety of power mixes, this article undertakes an analysis that combines two common ex-ante approaches – cheap talk and consequential script – with the ex-post certainty approach to calibrating hypothetical WTP responses. Based on a switching regression model that accounts for the potential endogeneity of respondent certainty, we find that while neither the cheap-talk nor the consequential script corrective bears on the estimates of WTP, there is evidence for a lower WTP among those respondents who classify themselves as definitely certain about their answers.