Computational aspects of nearly single-peaked electorates

<p>Manipulation, bribery, and control are well-studied ways of changing the outcome of an election. Many voting rules are, in the general case, computationally resistant to some of these manipulative actions. However when restricted to single-peaked electorates, these rules suddenly become eas...

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Main Authors: Erdelyi, G, Lackner, M, Pfandler, A
Format: Journal article
Published: Association for the Advancement of Artificial Intelligence 2017
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author Erdelyi, G
Lackner, M
Pfandler, A
author_facet Erdelyi, G
Lackner, M
Pfandler, A
author_sort Erdelyi, G
collection OXFORD
description <p>Manipulation, bribery, and control are well-studied ways of changing the outcome of an election. Many voting rules are, in the general case, computationally resistant to some of these manipulative actions. However when restricted to single-peaked electorates, these rules suddenly become easy to manipulate. Recently, Faliszewski, Hemaspaandra, and Hemaspaandra studied the computational complexity of strategic behavior in nearly singlepeaked electorates. These are electorates that are not single-peaked but close to it according to some distance measure.</p> <p>In this paper we introduce several new distance measures regarding single-peakedness. We prove that determining whether a given profile is nearly single-peaked is NP-complete in many cases. For one case we present a polynomial-time algorithm. In case the singlepeaked axis is given, we show that determining the distance is always possible in polynomial time. Furthermore, we explore the relations between the new notions introduced in this paper and existing notions from the literature.</p>
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spelling oxford-uuid:65025da2-eb1a-4834-9bb7-0d1c0762a6d72022-03-26T18:22:44ZComputational aspects of nearly single-peaked electoratesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:65025da2-eb1a-4834-9bb7-0d1c0762a6d7Symplectic Elements at OxfordAssociation for the Advancement of Artificial Intelligence2017Erdelyi, GLackner, MPfandler, A<p>Manipulation, bribery, and control are well-studied ways of changing the outcome of an election. Many voting rules are, in the general case, computationally resistant to some of these manipulative actions. However when restricted to single-peaked electorates, these rules suddenly become easy to manipulate. Recently, Faliszewski, Hemaspaandra, and Hemaspaandra studied the computational complexity of strategic behavior in nearly singlepeaked electorates. These are electorates that are not single-peaked but close to it according to some distance measure.</p> <p>In this paper we introduce several new distance measures regarding single-peakedness. We prove that determining whether a given profile is nearly single-peaked is NP-complete in many cases. For one case we present a polynomial-time algorithm. In case the singlepeaked axis is given, we show that determining the distance is always possible in polynomial time. Furthermore, we explore the relations between the new notions introduced in this paper and existing notions from the literature.</p>
spellingShingle Erdelyi, G
Lackner, M
Pfandler, A
Computational aspects of nearly single-peaked electorates
title Computational aspects of nearly single-peaked electorates
title_full Computational aspects of nearly single-peaked electorates
title_fullStr Computational aspects of nearly single-peaked electorates
title_full_unstemmed Computational aspects of nearly single-peaked electorates
title_short Computational aspects of nearly single-peaked electorates
title_sort computational aspects of nearly single peaked electorates
work_keys_str_mv AT erdelyig computationalaspectsofnearlysinglepeakedelectorates
AT lacknerm computationalaspectsofnearlysinglepeakedelectorates
AT pfandlera computationalaspectsofnearlysinglepeakedelectorates