Decentralization and Regionalist Parties’ Electoral Strength: What Causes What?

Traditionally studies on the causes and origins of regionalist party electoral strength have focused on sociological and historical specificities of the regions. Following part of the most recent scholarship, this paper aims to place the lens on the institutional environment in which these parties compete and, in particular, on the level of decentralization (i.e. level of regional authority). The paper considers regionalist parties’ electoral strength in both national and regional elections, also investigating the relationship between the two levels. Our analysis, based on a novel dataset of 136 regionalist parties across 320 regions and 18 countries, reaches interesting conclusions concerning spill-over effects and the differentiate effect of secondary independent variables (e.g. voting systems) across the two level of elections. As far as the impact of regional authority is concerned, we advance a preliminary and very tentative interpretation of the findings which leads us to conclude that the causal relationship works predominantly in the other way around: it is regionalist parties’ strength that affects the level of regional authority, rather than vice versa.