What is the relationship between the personalization of the vote and electoral volatility? The empirical evidence is limited and contradictory. Conventional wisdom says that personalization contributes to a general weakening of the ties between parties and voters, which should foster higher electoral volatility. Some studies suggest, however, that electoral volatility is lower in electoral systems with preferential voting for individual candidates. This implies that the relationship between personalization of the vote and electoral volatility is more complex than one would expect. In this paper, I will propose a theoretical framework for understanding and evaluating how the candidate-centredness of an electoral system and party system volatility are linked. I identify and measure three dimensions of candidate-centredness: object of vote, intra-party competition and freedom of choice. In the empirical part, I test whether or not party system volatility has increased at a greater rate over time in candidate-centred electoral systems compared to party-centred electoral systems, while controlling for influential third variables. In order to examine how electoral volatility varies across electoral systems and over time, I use data for lower house elections in all Western European countries between 1960 and 2016. Growth curve modelling within a multilevel framework is applied to identify different trajectories of party system volatility.
