Agreement, Diversity, and Polarization Indices for Approval Elections
Computer Science and Game Theory
2026-05-15 v1 Artificial Intelligence
Computers and Society
Multiagent Systems
Abstract
An index is a function that given an election outputs a value between 0 and 1, indicating the extent to which this election has a particular feature. We seek indices that capture agreement, diversity, and polarization among voters in approval elections, and that are normalized with respect to saturation. By the latter we mean that if two elections differ by the fraction of candidates approved by an average voter, but otherwise are of similar nature, then they should have similar index values. We propose several indices, analyze their properties, and use them to (a) derive a new map of approval elections, and (b) show similarities and differences between various real-life elections from Pabulib, Preflib and other sources.
Keywords
Cite
@article{arxiv.2605.14983,
title = {Agreement, Diversity, and Polarization Indices for Approval Elections},
author = {Piotr Faliszewski and Jitka Mertlová and Krzysztof Sornat and Stanisław Szufa and Tomasz Wąs},
journal= {arXiv preprint arXiv:2605.14983},
year = {2026}
}