Are the Europeans polarized? Levels and trends of ideological polarization in the 21st century

This paper seeks to assess the extent of political polarization in Europe in the last two decades, utilizing a novel measurement of mass political polarization applied to European Social Survey data. The main aim is to describe the developments of ideological polarization in Europe across time, polities and opinion dimensions. A secondary aim is to develop a more theoretically grounded measurement of polarization, based on DiMaggio, Evans and Bryson's (1996) seminal definition, while also departing from it in some important respects. While the concept of polarization has been extensively studied in recent years, it “appears not as one concept but many” (Bramson et al., 2017) even when considering only a qualified definition (i.e. mass ideological polarization). I argue that polarization should conceptually be understood as being about closeness to an in-group, as well as distance to out-groups, for the individual. In this spirit, I measure polarization as the extent to which opinions are dispersed and the extent to which variation in opinions is explained by party choice (i.e. sorted), as a multiplicative index. This conceptualization departs from other proposals such as polarization as (solely) dispersion, extremism, or sorting (Oscarsson et al., 2021)While these concepts are useful for describing characteristics of a (ideological) distribution, I argue that they are not the correct ways to identify ideological polarization. The results suggest that polarization varies significantly across European polities, and as a point of comparison, the US is not an outlier in this respect compared to the European countries. The general picture of change is that polarization has not increased, while a slight increase of polarization on immigration-related attitudes can be seen from 2014 to today. Bramson, A., Grim, P., Singer, D. J., Berger, W. J., Sack, G., Fisher, S., … Holman, B. (2017). Understanding polarization: Meanings, measures, and model evaluation. Philosophy of Science, 84(1), 115–159. http://doi.org/10.1086/688938 DiMaggio, P., Evans, J., & Bryson, B. (1996). Have American’s Social Attitudes Become More Polarized? American Journal of Sociology, 102(3), 690–755. Oscarsson, H., Bergman, T., Bergström, A., & Hellström, J. (2021). Demokratirådets rapport 2021: Polarisering i Sverige.