Sub-national Voting in Flux: Unravelling the Factors behind Volatility in European Regional Elections

European politics has experienced increased instability, with significant attention being paid to the volatility of national elections. However, there is still limited understanding of the underlying reasons for substantial vote shifts at the sub-national level, which extend beyond the typical fluctuations observed during electoral cycles. This study aims to explore the connection between regional and national elections and investigate other region-specific socio-economic and political factors that influence electoral instability within regions. The research delves into over 500 regional elections, analysing both total regional volatility and its territorial components while also examining processes of ‘political regeneration,’ marked by the emergence of new political actors and the decline of traditional ones. The findings reveal that while volatility between national parties in regional contests is mainly affected by national electoral dynamics, shifts in votes between region-specific parties are influenced by a combination of national and sub-national factors.