On swap convexity of voting rules

Obraztsova et al. (2013) have recently proposed an intriguing convexity axiom for voting rules. This axiom imposes conditions on the shape of the sets of elections with a given candidate as a winner. However, this new axiom is both too weak and too strong: it is too weak because it defines a set to...

Full description

Bibliographic Details
Main Authors: Obraztsova, S, Elkind, E, Faliszewski, P
Format: Conference item
Language:English
Published: AAAI Press 2020
_version_ 1826271335490256896
author Obraztsova, S
Elkind, E
Faliszewski, P
author_facet Obraztsova, S
Elkind, E
Faliszewski, P
author_sort Obraztsova, S
collection OXFORD
description Obraztsova et al. (2013) have recently proposed an intriguing convexity axiom for voting rules. This axiom imposes conditions on the shape of the sets of elections with a given candidate as a winner. However, this new axiom is both too weak and too strong: it is too weak because it defines a set to be convex if for any two elements of the set some shortest path between them lies within the set, whereas the standard definition of convexity requires all shortest paths between two elements to lie within the set, and it is too strong because common voting rules do not satisfy this axiom. In this paper, we (1) propose several families of voting rules that are convex in the sense of Obraztsova et al.; (2) put forward a weaker notion of convexity that is satisfied by most common voting rules; (3) prove impossibility results for a variant of this definition that considers all, rather than some shortest paths.
first_indexed 2024-03-06T21:55:03Z
format Conference item
id oxford-uuid:4ca0110a-6d3c-475d-9b05-43f723a42090
institution University of Oxford
language English
last_indexed 2024-03-06T21:55:03Z
publishDate 2020
publisher AAAI Press
record_format dspace
spelling oxford-uuid:4ca0110a-6d3c-475d-9b05-43f723a420902022-03-26T15:50:36ZOn swap convexity of voting rulesConference itemhttp://purl.org/coar/resource_type/c_5794uuid:4ca0110a-6d3c-475d-9b05-43f723a42090EnglishSymplectic ElementsAAAI Press2020Obraztsova, SElkind, EFaliszewski, PObraztsova et al. (2013) have recently proposed an intriguing convexity axiom for voting rules. This axiom imposes conditions on the shape of the sets of elections with a given candidate as a winner. However, this new axiom is both too weak and too strong: it is too weak because it defines a set to be convex if for any two elements of the set some shortest path between them lies within the set, whereas the standard definition of convexity requires all shortest paths between two elements to lie within the set, and it is too strong because common voting rules do not satisfy this axiom. In this paper, we (1) propose several families of voting rules that are convex in the sense of Obraztsova et al.; (2) put forward a weaker notion of convexity that is satisfied by most common voting rules; (3) prove impossibility results for a variant of this definition that considers all, rather than some shortest paths.
spellingShingle Obraztsova, S
Elkind, E
Faliszewski, P
On swap convexity of voting rules
title On swap convexity of voting rules
title_full On swap convexity of voting rules
title_fullStr On swap convexity of voting rules
title_full_unstemmed On swap convexity of voting rules
title_short On swap convexity of voting rules
title_sort on swap convexity of voting rules
work_keys_str_mv AT obraztsovas onswapconvexityofvotingrules
AT elkinde onswapconvexityofvotingrules
AT faliszewskip onswapconvexityofvotingrules