Can a Repeated Opt-Out Reminder mitigate hypothetical bias in discrete choice experiments? An application to consumer valuation of novel food products

In this paper, we test whether a Repeated Opt-Out Reminder (ROOR) can mitigate hypothetical bias in stated discrete choice experiments (DCE). The data originate from a field experiment concerning consumer preferences for a novel food product made from cricket flour. Utilising a between-subject design with three treatments, we find significantly higher marginal willingness-to-pay values in hypothetical than in nonhypothetical settings, confirming the presence of hypothetical bias. Comparing this to a hypothetical setting where the ROOR is introduced, we find that the ROOR effectively mitigates hypothetical bias for one attribute and significantly reduces it for the rest of the attributes.