Congruence Between Regional and National Elections

The number of regional elections and what is at stake at these elections have increased considerably over the past decades. Yet the interpretation of regional election results lags behind, in particular explanations for when and how regional election results deviate from national election results. This article conceptualizes congruence of the vote in three different ways that make it possible to assess the contribution of three competing theoretical approaches in explaining variation in dissimilarity between vote shares across space and time. These approaches are second-order election theory, regional authority and territorial cleavages. The hypotheses are tested against a data set containing the results of more than 4,000 regional and national elections held in 360 regions in 18 countries. It appears that the depth of territorial cleavages explains variation across space, but to understand change over time one needs to consider institutional authority and second-order election effects.