Election turnout statistics in many countries: similarities, differences, and a diffusive field model for decision-making

TL;DR

This study analyzes election turnout data from 77 elections across 11 countries, revealing universal spatial correlation patterns and proposing a diffusive field model to explain decision-making influences.

Contribution

It extends previous findings on French elections to a broader set of countries and introduces a decision model incorporating idiosyncratic, local, and long-range influences.

Findings

Spatial correlation of turnout decays logarithmically with distance

Different countries show varying levels of local heterogeneity

Evidence of herding behavior in some countries

Abstract

We study in details the turnout rate statistics for 77 elections in 11 different countries. We show that the empirical results established in a previous paper for French elections appear to hold much more generally. We find in particular that the spatial correlation of turnout rates decay logarithmically with distance in all cases. This result is quantitatively reproduced by a decision model that assumes that each voter makes his mind as a result of three influence terms: one totally idiosyncratic component, one city-specific term with short-ranged fluctuations in space, and one long-ranged correlated field which propagates diffusively in space. A detailed analysis reveals several interesting features: for example, different countries have different degrees of local heterogeneities and seem to be characterized by a different propensity for individuals to conform to the cultural norm. We furthermore find clear signs of herding (i.e. strongly correlated decisions at the individual level) in some countries, but not in others.