Comparing Ways of Obtaining Candidate Orderings from Approval Ballots

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Delemazure, Théo, Dong, Chris, Peters, Dominik, Tydrichová, Magdaléna
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866907893282897920
author Delemazure, Théo
Dong, Chris
Peters, Dominik
Tydrichová, Magdaléna
author_facet Delemazure, Théo
Dong, Chris
Peters, Dominik
Tydrichová, Magdaléna
contents To understand and summarize approval preferences and other binary evaluation data, it is useful to order the items on an axis which explains the data. In a political election using approval voting, this could be an ideological left-right axis such that each voter approves adjacent candidates, an analogue of single-peakedness. In a perfect axis, every approval set would be an interval, which is usually not possible, and so we need to choose an axis that gets closest to this ideal. The literature has developed algorithms for optimizing several objective functions (e.g., minimize the number of added approvals needed to get a perfect axis), but provides little help with choosing among different objectives. In this paper, we take a social choice approach and compare 5 different axis selection rules axiomatically, by studying the properties they satisfy. We establish some impossibility theorems, and characterize (within the class of scoring rules) the rule that chooses the axes that maximize the number of votes that form intervals, using the axioms of ballot monotonicity and resistance to cloning. Finally, we study the behavior of the rules on data from French election surveys, on the votes of justices of the US Supreme Court, and on synthetic data.
format Preprint
id arxiv_https___arxiv_org_abs_2405_04525
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Comparing Ways of Obtaining Candidate Orderings from Approval Ballots
Delemazure, Théo
Dong, Chris
Peters, Dominik
Tydrichová, Magdaléna
Computer Science and Game Theory
To understand and summarize approval preferences and other binary evaluation data, it is useful to order the items on an axis which explains the data. In a political election using approval voting, this could be an ideological left-right axis such that each voter approves adjacent candidates, an analogue of single-peakedness. In a perfect axis, every approval set would be an interval, which is usually not possible, and so we need to choose an axis that gets closest to this ideal. The literature has developed algorithms for optimizing several objective functions (e.g., minimize the number of added approvals needed to get a perfect axis), but provides little help with choosing among different objectives. In this paper, we take a social choice approach and compare 5 different axis selection rules axiomatically, by studying the properties they satisfy. We establish some impossibility theorems, and characterize (within the class of scoring rules) the rule that chooses the axes that maximize the number of votes that form intervals, using the axioms of ballot monotonicity and resistance to cloning. Finally, we study the behavior of the rules on data from French election surveys, on the votes of justices of the US Supreme Court, and on synthetic data.
title Comparing Ways of Obtaining Candidate Orderings from Approval Ballots
topic Computer Science and Game Theory
url https://arxiv.org/abs/2405.04525