Does the Electoral System Foster a Predominant Party System? Evidence from Turkey

This paper discusses the role of the electoral system in making the Justice and Development Party (AKP) dominant. Drawing on Sartori's framework, we first clarify the concept of a predominant party system. Second, we examine the impact of the electoral system on the emergence of a predominant party system in Turkey. Analysing election results, we argue that the electoral system fosters dominance in three ways. First, a combination of electoral formula, national threshold and district threshold leads to over-representation of large parties and under-representation of small ones. Second, the fear of a wasted vote due to the high threshold prompts voters to support their second-best option, which concentrates the votes among large parties. Finally, the electoral system increases electoral turnout rates by extending polarization.