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arXiv · 2505.01395

The Proportional Veto Principle for Approval Ballots

Daniel Halpern·Ariel D. Procaccia·Warut Suksompong
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Abstract

The proportional veto principle, which captures the idea that a candidate vetoed by a large group of voters should not be chosen, has been studied for ranked ballots in single-winner voting. We introduce a version of this principle for approval ballots, which we call flexible-voter representation (FVR). We show that while the approval voting rule and other natural scoring rules provide the optimal FVR guarantee only for some flexibility threshold, there exists a scoring rule that is FVR-optimal for all thresholds simultaneously. We also extend our results to multi-winner voting.

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Daniel Halpern, Ariel D. Procaccia, Warut Suksompong. 2025-05-02. The Proportional Veto Principle for Approval Ballots. https://arxiv.org/abs/2505.01395

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