September 18, 2019 - Uncertainty and subjective beliefs improve truth-telling in voting:
Congratulations to Dr. Eric Bahel, whose paper titled 'Strategyproof Choice of Social Acts' (co-authored with Dr. Yves Sprumont) has been accepted for publication in the American Economic Review. Truth-telling is a central requirement in mechanism design; it says that a mechanism should induce agents to reveal the truth about their preferences. A classic impossibility result in social choice theory (known as the Gibbard-Satterthwaite theorem) states that, when society must choose between three or more alternatives, there exists no truth-telling voting mechanism that is not dictatorial. Eric and Yves consider the more general framework where there are many possible future states of nature and agents have subjective beliefs about the likelihood of each state. Their work shows that, with subjective expected utility preferences, one can potentially design truth-telling voting mechanisms that are responsive to the preferences of all voters. Moreover, the authors characterize and describe the set of voting mechanisms that are truth-telling and satisfy the unanimity axiom (i.e., society must choose the act viewed as the favorite by every agent whenever such an act exists). This work has important applications for the design of collective choice mechanisms. The full paper is available here for further details.