Abstract : Background The choice of elicitation format is a crucial but tricky aspect of stated preferences surveys. It affects not only the quantity and quality of the information collected on respondents’ willingness to pay (WTP) but also the potential errors/biases that prevent their true WTP from being observed. Objectives We propose a new elicitation mechanism, the circular payment card (CPC), and show that it helps overcome the drawbacks of the standard payment card (PC) format. It uses a visual pie chart representation without start or end points: respondents spin the circular card in any direction until they find the section that best matches their true WTP. Methods We performed a contingent valuation survey regarding a mandatory health insurance scheme in Tunisia, a middle-income country. Respondents were randomly allocated into one of three subgroups and their WTP was elicited using one of three formats: open-ended (OE), standard PC and the new CPC. We compared the elicited WTP. Results We found significant differences in unconditional and conditional analyses. Our empirical results consistently indicated that the OE and standard PC formats led to significantly lower WTP than the CPC format. Conclusion Overall, our results are encouraging and suggest CPC could be an effective alternative format to elicit ‘true’ WTP.
