Patterns of Transformation of Party Systems in EU Countries: Direction of Changes and Reasons for Differences

The article presents an original classification of patterns of transformation of party systems in EU countries under the influence of the institutionalization of a new post-industrial cleavage. Drawing on theories of cleavage and spatial competition and using party positioning databases, electoral indices and statistics, the author attempts to identify the main trajectories of the transformation of the European party systems between 1990 and 2023 and identify factors that explain the differences between them. The study identified five patterns associated with the effects of two key parameters. The first one is the structural specificity of the conditions of party competition in post-communist and other EU countries, associated with the difference between the old structured and new volatile party systems. The second parameter is the type of a country’s party-political system in accordance with Arend Lijphart’s classification — either majoritarian-polarized or coalition-consensus. While under majoritarian system the institutionalization of a new cleavage often gave rise to a radical breakdown of the old configuration of parties with the emergence of powerful populist forces, under consensus system — a smooth increase in fragmentation with the outflow of votes in favor of various new parties and the complication of the process of forming coalitions. For a number of countries other factors, such as the level of socio-economic development, ethnocentricity of politics, the type of electoral system and the stability of the welfare state appeared relatively important. In contrast, hypotheses about the significance of the initial configuration of party systems, the timing of formation of new parties and the geographical proximity of countries were not confirmed.