Flexible institutional designs and executive politics in semi-presidential European regimes

I challenge the common assumption in the literature that executives' powers vis-a-vis each other can change solely as the result of the norms and practices consequential of institutional change. I argue instead that a fixed institutional design can also generate changes in power distribution, through informal rules, norms, and practices of an institution, without necessitating formal or constitutional transformation. I contribute to both the literature on institutional change and the literature on democratic regimes by providing a systematic assessment of the factors that explain why there are shifts in the power distribution between political executives in semi-presidential regimes. I propose to test the key factors of power variation proposed in the literature on the power relationship between presidents and prime ministers, through two major studies, France's Fifth Republic and post-1993 Ukraine, and three suggestive studies of Finland, post-1993 Russia, and post-1990 Poland.;This study tests those three set of theoretical explanations through historical analysis and develop a model explaining the causes of changes in the power relationship between presidents and prime ministers in semi-presidential regimes. More precisely, I try to assess the importance of the institutional design in semi-presidential regimes versus the impact of non-institutional factors, highlighting the role of the specific national context (partisan politics, non-institutional factors) in shaping political practice between political executives.;The examination of institutional practice through the lens of the power relationship between political executives in the semi-presidential regimes demonstrates that this claim needs to be revisited. Theoretically, the results of the historical analysis support historical, sociological, and normative institutionalist theories, which have stressed the need to go beyond orthodox institutionalist theories. Globally, results show the theoretical need to capture the political, social, international, and economic context in order to define and predict the power distribution between political actors in semipresidential regimes. This study highlights the need to dismiss the claim that institutional unpredictability is solely observed in unstable country and showcases the complex dynamic that (a) institutions adapt to their political environment, while (b) the political environment adapts to the institutions.