Explaining the Development of Party Organization: A Regime Perspective

This paper argues that parliamentarianism strengthens party organization and party unity. The reason is that parliamentary elections and the behavior of parties in parliament are crucial for parties to assume power, which in turn means that party organization has direct effects on the probability of getting into office. I test the argument by employing a new data set on the historical evolution of parliamentarianism in Europe up until today that I link to V-Dem’s data on party development. Graphically and quantitatively, I show that as a response to the development of parliamentarianism in different European countries, party organization developed. The results hold even when accounting for other factors such as suffrage and electoral rules. My argument is further corroborated by the finding that the effect of parliamentary development is the strongest on party organization in parliament. The results shed light on the differences in party organization between parliamentary and presidential systems, suggesting that these are explained by the difference in parliament’s role in government formation and termination between the two systems, and that the type of regime thus explains the strength of party organization rather than vice versa.