Indirect questioning as a debiasing mechanism in preference elicitation for sustainable food? First evidence from a Discrete Choice Experiment

Indirect questioning (IQ), i.e., asking respondents to predict the behavior of others, has been employed in stated preference studies as WTP elicitation technique. This technique, also referred to as Inferred Valuation, represents a promising approach for reducing hypothetical bias when it is not possible to sell actual goods to participants and when the social desirability bias is a potential problem (e.g., preferences for sustainable food attributes). To date, several issues associated to the use of IQ have not been adequately investigated. We carried out a Discrete Choice Experiment on field to verify the effects on estimated WTPs of: i) different IQ framing; ii) monetary incentives associated to predictions; and iii) the order of presentation. First, by employing two different question formats (e.g. asking to predict others’ behavior in a real market situation or in hypothetical situations) we uncover how respondents are able to anticipate the tendency of others to provide socially desirable answers. Second, monetary incentives create a rewarding environment that indirectly affects WTPs obtained from direct questions. Third, we uncover a potential ‘debiasing’ effect on WTPs of asking respondents to make predictions about others’ before stating their own preferences, which could have interesting implications for practitioners.