Process matters: the variegated effects of municipal amalgamation features on voter turnout revealed in a 10-country comparative investigation

Most literature finds a detrimental effect of amalgamation on voter turnout in municipal elections. Some other studies reveal instead null or even positive effects. We argue that this inconsistency derives from the fact that previous research has only analysed the amalgamation/turnout relation in single case studies. The contribution of this article is therefore twofold. First, it proposes a unified framework to investigate the amalgamation/turnout relation in comparative perspective, which clarifies the shortcut between size and amalgamation, disentangles the multifaced nature of municipal amalgamation, and outlines clear testable hypotheses related to its implementation – both at the national and at the local level. Secondly, it provides an original 10-European-country dataset of municipal amalgamations in the last decades (comprising Albania, Austria, Denmark, Finland, Germany, Iceland, Italy, Luxembourg, the Netherlands, and Norway) to empirically verify such hypotheses concerning the effects of the amalgamation features on voter turnout. Our study crucially reveals the relevance of the characteristics of the amalgamation process. When the amalgamation is imposed by the national government, turnout is particularly low, similarly to when the amalgamation occurs independently from a wide reform scheme. On the other hand, municipal turnout after amalgamation is higher when a larger number of municipalities are merged and when the amalgamated municipalities had a similar population before being merged. Moreover, our empirical evidence confirms the importance of traditional second-order predictors of turnout in municipal elections, even with specific reference to the post-amalgamation elections. Conversely, in such elections, the overall size of the (final) municipality is not a significant predictor of voter turnout.