Robust Committee Voting, or The Other Side of Representation

Prelegent(ci)

Krzysztof Sornat

Afiliacja

AGH University of Science and Technology

Język referatu

angielski

Termin

26 czerwca 2025 12:00

Informacje na temat wydarzenia

online

Seminarium

Seminarium „Gry, mechanizmy i sieci społeczne”

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We study approval-based committee voting from a novel perspective. While extant work largely centers around proportional representation of the voters, we shift our focus to the candidates while preserving proportionality. Intuitively, candidates supported by similar voter groups should receive comparable representation. Since deterministic voting rules cannot achieve this ideal, we develop randomized voting rules that satisfy ex-ante neutrality, monotonicity, and continuity, while maintaining strong ex-post proportionality guarantees. Continuity of the candidate selection probabilities proves to be the most demanding of our ex-ante desiderata. We provide it via voting rules that are algorithmically stable, a stronger notion of robustness which captures the continuity of the committee distribution under small changes.

Our paper hits the EC-25 stage in two weeks, but you can already check it out---it went live on arXiv this Monday: https://arxiv.org/abs/2506.18643

This is a joint work with Gregory Kehne and Ulrike Schmidt-Kraepelin.

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