From nations to regions: Electoral volatility in European multi-level politics

European politics has experienced increasing turbulence, with much focus on the volatility of national elections. However, it remains unclear whether such instability extends to the sub-national level. This article investigates patterns of electoral instability in regional elections and their relationship with volatility at the national level. Drawing on a quantitative analysis of approximately 500 regional elections across 58 regions in four Western European countries, it disaggregates regional volatility into its territorial components and examines processes of political regeneration, marked by the rise of new parties challenging established ones. The findings show that regional elections often mirror the volatile dynamics observed nationally. However, this link weakens in sub-national systems dominated by regionalist parties, characterised by stronger meso-level institutions and higher levels of regional economic prosperity. These results highlight the importance of territorial context in shaping manifestations of electoral instability and contribute to a more nuanced understanding of multi-level party system change.