Date: Wednesday, December 14th, 2022
9:00 am – 10:00 am Pacific Time
12:00 pm – 1:00 pm Eastern Time
Location: Weekly Seminar, Zoom
Title: The Power of Altruism in Voting
A key promise of democratic voting is that, by accounting for all constituents’ preferences, it produces decisions that benefit the constituency overall. It is alarming, then, that all deterministic voting rules have unbounded distortion: that is, all such rules – even under reasonable conditions – will sometimes select outcomes that give essentially zero value to voters overall.
In our paper, A Bit of Altruism Can Curb Distortion, we show that this problem is mitigated by voters being altruistic: that is, when deciding how to rank alternatives, voters weigh not only their own interests, but also the interests of others. We first generalize the standard voting model to capture this altruistic behavior, and then show that a small amount of altruism across voters can substantially limit distortion for many voting rules. We further show that the benefits of altruism are robust to various adversarial conditions likely to exist in practice. Most importantly, this result is actionable in that it suggests an implementable way to help elections produce higher-welfare outcomes: democratic deliberation, which is believed to increase voters’ tendency to weigh the common good when deciding how to vote.
Bailey Flanigan is a fourth-year PhD student at Carnegie Mellon University, advised by Ariel Procaccia. Her work uses the tools of theoretical CS and AI to design more effective democratic processes (e.g., citizens’ assemblies). She has also recently become interested in practice-driven questions related to online learning and algorithms with predictions. Outside of research, she is passionate about equitable education and led the CS-JEDI project at CMU.