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arXiv · 2608.21202

Half Veto, Half Maximal Lottery, Five-halves Distortion

Qilin Ye
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Abstract

We give a randomized voting rule with expected metric distortion $5/2$, improving the previous best upper bound of $2.753$. Our rule is the equal mixture of a Maximal Lottery [CRWW24] and a lottery obtained by averaging scores in Simultaneous Plurality Veto [KK23] over time. We further show that $5/2$ is optimal within a broader family that allows profile-dependent mixing weights and arbitrary, possibly adaptive, weights over the veto process.

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Qilin Ye. 2026-08-21. Half Veto, Half Maximal Lottery, Five-halves Distortion. https://arxiv.org/abs/2608.21202

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