2021/07/02 by Manon Revel, Tao Lin, Revel, Manon +3
Arts and Humanities · Computer Science · Decision Sciences · Economics, Econometrics and Finance · #Artificial Intelligence (cs.AI) #Computer Science and Game Theory (cs.GT) #Epistemology, Ethics, and Metaphysics #FOS: Computer and information sciences #Game Theory and Applications #Game Theory and Voting Systems #cs.AI #cs.GT
paper · pdf · doi:10.48550/arxiv.2107.01042
arxiv created 2021/07/02 · openalex publication_date 2021/07/02 · arxiv updated 2021/07/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We analyze the optimal size of a congress in a representative democracy. We take an epistemic view where voters decide on a binary issue with one ground truth outcome, and each voter votes correctly according to their competence levels in [0, 1]. Assuming that we can sample the best experts to form an epistemic congress, we find that the optimal congress size should be linear in the population size. This result is striking because it holds even when allowing the top representatives to be accurate with arbitrarily high probabilities. We then analyze real world data, finding that the actual sizes of congresses are much smaller than the optimal size our theoretical results suggest. We conclude by analyzing under what conditions congresses of sub-optimal sizes would still outperform direct democracy, in which all voters vote.