Honesty Via Choice-Matching

We introduce choice-matching, a class of mechanisms for eliciting honest responses to a multiplechoice question (MCQ), as might appear in a market research study, opinion poll or economicsexperiment. Under choice-matching, respondents are compensated through an auxiliary task, e.g.,a personal consumption choice or a forecast. Their compensation depends both on their performance on the auxiliary task, and on the performance of those respondents who matched theirresponse to the MCQ. We give conditions for such mechanisms to be strictly truth-inducing, focusing on a special case in which the auxiliary task is to predict the answers of other respondents