Universality in voting behavior: an empirical analysis

TL;DR

This study empirically confirms a universal distribution pattern in candidate vote shares across multiple countries with proportional elections, highlighting the importance of party affiliation in electoral performance.

Contribution

First comprehensive assessment of universality in voting behavior, demonstrating its validity across diverse electoral systems and emphasizing the influence of party structures.

Findings

Universal vote distribution observed in 15 countries with proportional systems.

Discrepancies linked to specific election rule differences.

Party affiliation is crucial for accurate modeling of candidate performance.

Abstract

Election data represent a precious source of information to study human behavior at a large scale. In proportional elections with open lists, the number of votes received by a candidate, rescaled by the average performance of all competitors in the same party list, has the same distribution regardless of the country and the year of the election. Here we provide the first thorough assessment of this claim. We analyzed election datasets of 15 countries with proportional systems. We confirm that a class of nations with similar election rules fulfill the universality claim. Discrepancies from this trend in other countries with open-lists elections are always associated with peculiar differences in the election rules, which matter more than differences between countries and historical periods. Our analysis shows that the role of parties in the electoral performance of candidates is crucial: alternative scalings not taking into account party affiliations lead to poor results.