Is the Whole the Product of the Parts? the Institutionalization of European Political Parties and Party Systems Since 1848

The paper departs from a theoretical distinction between the party-level and the systemic level analysis of party politics (Randall and Svåsand, 2002). Following a conceptual re-examination of these two phenomena, we first review the existing literature on party and party system institutionalization, indicating limitations and inconsistencies, before offering a new analytical model which, on the one hand, focuses on the party-specific parameters of the system (party institutionalization) and, on the other, concentrates on the interactions of the political parties (party system institutionalization).

Therefore, while the institutionalization of political parties is understood as progress in two dimensions: roots in society and level of organization; party system institutionalization is considered to be the process by which the patterns of inter-party interaction become routine, predictable and stable over time. This will be followed by a contrast between data showing the degree of party institutionalization and the data indicating the level of party system institutionalization in 65 European democracies between 1848 and 2015. For the latter, we will introduce a new composite index of party system institutionalization (Casal Bértoa and Enyedi, 2016) which, looking at the predictability in the structure of inter-party competition at the time of government formation, captures the degree to which the patterns of partisan interaction can be considered to be stable over time.

The paper will demonstrate the complex relationship between party and party system institutionalization, and will argue that the former should be considered a source but not a symptom of the latter.