Effects of semi-presidentialism on party system institutionalization: does the shift to premier-presidentialism increase party system institutionalization?
Party system institutionalization has been extensively studied in the political science scholarship, however semi-presidentialism which saw the resurgence of interest among transitional countries, and as a result also in academia at the end of the 1990s, remains loosely treated in the relevant literature. Even the studies which include semipresidentialism as a regime type, tend to overlook the significant institutional differences within semi-presidentialism. The aim of the current paper is to contribute to the understanding of party systems institutionalization in semi-presidential countries by discriminating between two sub-types within the regime which create distinct institutional arrangements, systems of accountability, and incentives for the parties involved in this system. Underlying assumption behind this research is that the shift from president-parliamentary to the premier-presidential system produces increased institutionalization in party systems, based on the more individual-centric design of the first sub-type and the more partyoriented premier-presidential system in the second. By mapping out the differences within the semi-presidential regime the paper also tries to refine the existing measurement of the party system institutionalization, in order to better account for the systematic character of interactions between parties in this regime. In order to test the hypothesis five countries which underwent the shift from presidentparliamentarism to premier-presidneitalism are examined in this study. In terms of research design, the case selection employed here will permit a study of the effects of regime type on party system institutionalization, since all five cases had underdeveloped party systems at a time of constitutional amendment that brought semi-presidentialism. The results largely support the hypothesis, four of five cases showed increased levels of PSI after the shift to premier-presidentialism, while one case deviated. Based on the empirical results, conclusion is drawn that under-institutionalized party systems under president-parliamentarism, will improve their performance if they switch to the more parti-centric system.