Inequality, identity, and partisanship: How redistribution can stem the tide of mass polarization

Alexander J Stewart,Joshua B Plotkin,Nolan Mccarty

doi:10.1073/pnas.2102140118

Abstract

The form of political polarization where citizens develop strongly negative attitudes toward out-party members and policies has become increasingly prominent across many democracies. Economic hardship and social inequality, as well as intergroup and racial conflict, have been identified as important contributing factors to this phenomenon known as "affective polarization." Research shows that partisan animosities are exacerbated when these interests and identities become aligned with existing party cleavages. In this paper, we use a model of cultural evolution to study how these forces combine to generate and maintain affective political polarization. We show that economic events can drive both affective polarization and the sorting of group identities along party lines, which, in turn, can magnify the effects of underlying inequality between those groups. But, on a more optimistic note, we show that sufficiently high levels of wealth redistribution through the provision of public goods can counteract this feedback and limit the rise of polarization. We test some of our key theoretical predictions using survey data on intergroup polarization, sorting of racial groups, and affective polarization in the United States over the past 50 y.

Highlights

The form of political polarization where citizens develop strongly negative attitudes toward out-party members and policies has become increasingly prominent across many democracies
We show that risk-averse attitudes toward other identity groups can transform into affective polarization between supporters of different political parties, through a process of cultural evolution
Our model provides a framework for connecting the effects of intergroup animus, economic adversity, and mass political polarization through the lens of cultural evolution [38, 39]

Summary

Introduction

The form of political polarization where citizens develop strongly negative attitudes toward out-party members and policies has become increasingly prominent across many democracies. We show that, when agents attend to both group and partisan identities in choosing interaction partners, this stimulates both the evolution of behavioral strategies that polarize along party lines and the sorting of group identities along party lines These behaviors evolve in response to shifts in the economic environment and underlying inequality. The political polarization of citizens is increasingly a concern throughout the world, as populist movements challenge mainstream parties in efforts to disrupt established institutions and democratic norms [1] Such trends have been especially manifest in the United States, where they have culminated in political violence such as at the Unite the Right rally in Charlottesville and the storming of the Capitol during the certification of the 2020 presidential election [2] That work continues to show that the public’s attitudes on policy issues have remained stable and centrist over many decades [4] (but see ref. 5; this debate is reviewed in ref. 6)

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Conclusion