Quadratically Normalized Utilitarian Voting (Job market paper), with Marcus Pivato, 2024  View PDF 

Abstract: What if a voter could declare how much they value alternatives rather than simply reporting their first preference or ranking the alternatives? We propose a new voting mechanism in which voters simultaneously report their von Neumann-Morgenstern (vNM) utility functions across multiple decision problems, each of which has a finite number of alternatives. Each voter must report a real-valued valuation" for each alternative of each decision. Each voter's valuation vector is rescaled to have unit magnitude (where this magnitude is measured using a specially constructed quadratic form). We show that it is a dominant strategy for each voter to reveal her true vNM utility function. With a very high probability, the mechanism selects the alternative that maximizes a weighted utilitarian social welfare function. Therefore, the mechanism thus achieves efficient outcomes while allowing voters to express the intensity of their preferences. The mechanism does not use money, and does not assume quasilinear utilities.

An Incentive-Compatible Utilitarian Voting Procedure for Permanent Citizens' Assemblies, with Marcus Pivato, 2024 View PDF 

Abstract: We consider a committee of voters randomly drawn from a larger population facing an infinite sequence of voting decisions, akin to a citizen jury. We propose a new voting mechanism for such juries where each voter has a privately known von Neumann-Morgenstern (vNM) utility function over social alternatives in each decision, and is asked to declare a real-valued ‘valuation’ for each alternative of a decision. We further impose a probability of being removed from the committee for the next decision dependent on the declaration of a voter. If a voter is removed, then they are replaced by some non-committee member from the larger population. We show that when the voters’ discount factor is large enough, imposing a probability equal to a scalar multiple of the Vickrey-Clarke-Groves tax leads to truthful revelation by the voters and consequently utilitarian efficient outcomes at a Bayesian Nash equilibrium.