Electoral systems have an enormous importance on how political power is distributed, on governability and the dynamics of representation of any given democratic society. Political science has traditionally considered electoral systems to be stable institutions and has paid more attention to understand how political parties adapt to the electoral rules than to how “electoral institutions themselves are adapted by political parties” (Benoit 2004). However, given their importance, unveiling the factors that influence the change and the choice of electoral rules is crucial and an increasing number of studies has addressed the issue since the 1990s. <p>This dissertation lies at the crossroads between traditional explanations of the stability of electoral systems and the more recent interpretations of electoral system change. Through three empirical parts, this thesis shows how these literatures are reconcilable and complementary. This study encompasses a comprehensive set of explicative factors at the micro, meso and macro levels that shed light on the incentives and barriers to reform electoral systems. Methodologically, the large-N approach of this thesis goes beyond the usual case studies and small-N analyses that characterize the field of electoral system change. Besides, the consideration of cases of reforms and cases of stability contributes to a better understanding of the determinants of electoral system change. While traditional accounts of electoral system change are predominantly based on political parties’ self-interest, this study demonstrates that the context matters. In this regard, this dissertation has three main findings. <p>Firstly, this study calls into question the body of literature addressing the change of electoral institutions by analyzing the impact of different barriers in the success of reform debates. At the party level, it shows how intraparty division can constitute an important factor to explain institutional inertia. The analysis is based on the responses of Irish Members of Parliament (Teachtaí Dala, or TDs) to a number of survey items designed to measure their evaluations of the current electoral system. The study discusses how the heterogeneity of preferences within parties over this issue may act as a barrier for reform. Besides, at the micro level, it sheds light on the determinants of individuals’ incentives to support reform. Beyond the classical power-seeking motivations, individual legislators also appear to be driven by values and attitudes about the quality of democracy.<p>Secondly, this thesis focuses on institutional contexts. This study analyzes the capacity of institutions to deter reforms using empirical evidence of the occurrence of reforms and the duration of electoral systems in 17 European countries. Drawing on Lijphart’s framework of the patterns of democracy, this research analyzes the extent to which the elements that differentiate between majoritarian and consensus democracies can hinder electoral reforms. On the one hand, it shows the impact of individual institutions on the occurrence of reform and the duration of electoral systems. It demonstrates that higher numbers of veto players, more proportional electoral systems, limited vested interests of the incumbent parties, constitutional rigidity and the existence of judicial review can reduce the likelihood of reform. On the other hand, this study demonstrates that the different combinations of institutional elements provide important explanatory leverage on the duration of electoral systems. In this regard, contrary to what is often assumed, it is shown that the occurrence of electoral reforms is linked to the incumbents’ capacity to develop their preferred policies. Those systems in which power is more concentrated, that is majoritarian systems, appear to be those in which electoral systems reforms are more frequent. <p>Finally, the thesis explores the impact of external shocks on the likelihood of reform. On the basis of an analysis of a dataset of electoral reforms that have been enacted in Europe since 1945, this study demonstrates that economic crises and citizens’ dissatisfaction with democracy are related to the introduction of electoral reforms. However, the mechanism is mediated by the existence of new parties that capitalize on this dissatisfaction and that can threaten the established parties. In these circumstances, restrictive reforms – those that aim at hindering the entry of new parties - are more likely to be introduced, though too late to prevent the entry of these newcomers.<p> / Doctorat en Sciences politiques et sociales / info:eu-repo/semantics/nonPublished