Ideological Polarization

Beginning with Sartori (1976)’s seminal work on party systems, polarization, which he defined as growing distance between political actors, has been a central theme in the literature on multiparty systems in Europe and beyond (Dassonneville and Çakır 2021). Sartori (1976), and most of the literature until recently, understood distance in a purely programmatic sense, often along a single left-right dimension. In its simplest form, ideological polarization can be measured as the distance between the policy positions of parties or their supporters, but more sophisticated methods also take into account the full distribution of opinions across the political spectrum.

Polarization is different from party-system fractionalization (Dalton 2008), which measures the distribution of vote or seat shares across parties, but can be considered a component of politicization (Hutter and Grande 2014). Although conceptually distinct, polarization tends to correlate with party-system fractionalization because many measures, as we will see in the next section, integrate vote and seat shares. In the literature on the politicization of the EU, politicization is defined as the extent to which the EU is both a salient and politically contested, i.e., polarized, political issue.

Measures

Use cases

Publications that address ideological polarization: