Political Polarization and the Dynamics of Ideological Congruence

• In Event: Polarization and Dimensionality in Advanced Industrial Societies

Abstract

The responsible party model of democracy requires close correspondence between what citizens demand and what they get from their elected representatives. While governments are expected to be responsive to the policy demands of the public, we also expect the public to respond to government policies. Despite the well-established literatures on ideological congruence and on democratic representation, few previous works examine how parties and citizens update their ideological positions in response to perturbations in this representative relationship. Rather, most tackle with the so-called ``ideological congruence controversy'' that party systems under PR and SMD rules do not differ much in their respective levels of ideological congruence despite the varied numbers of party policy choices they provide their electorates.

In this paper, we focus on the interaction of party and electoral polarization to explain the variation in ideological congruence across electoral system types, and within particular party systems over time. To the extent that party polarization is not coupled with electoral polarization, we should expect to observe lower ideological congruence in polarized party systems. If electorates are equally polarized in their ideological demands, however, polarized party policy offerings are expected to increase congruence. The effects of party and electoral polarization on ideological congruence are however conditional on electoral rules, which influence the number of party offerings and the extent to which they are proportionally represented in the legislature.

To assess our expectations we collected survey data on citizen and party positions in 19 established democracies. This original compilation of survey data covers 157 general elections between 1971 and 2017. While recent literature on congruence has also employed survey data on respondents' self-reported positions and perceptions of party positions, their spatial and temporal coverage has been quite limited. In contrast, amassing over 40 years of survey data allows us to employ error-correction models to assess the short- and the long-term effects of party and electoral polarization on ideological congruence. In addition, we examine the degree to which ideological congruence between voters and parties under SMD and PR electoral rules correct deviations and revert back to their equilibrium states following perturbations in this relationship.

Our empirical analyses suggest that party systems with lower levels of fragmentation and polarization show higher congruence. When both voters and parties are polarized, party systems under PR rules show higher ideological congruence. Highlighting the interactive effects of party and electoral polarization on ideological congruence, these findings present a theoretical explanation for contradictory findings in previous literature. In the concluding section, we discuss the roles party and electoral polarization play for democratic representation.

Authors

• Robin E. Best, Binghamton University (SUNY)

• Mert Moral, Sabancı University