The Mixed-Member Majoritarian Electoral System, Effective Regional Political Leaders, and the Regional Hegemonic Party System: A Panel Analysis of the South Korean Case

This paper analyzes the effects of the “mixed-member majoritarian” (MMM) electoral system and effective regional political leaders on the mitigation of the regional hegemonic party system in Korea, while controlling for the influence of regional economic conditions and the 2004 National Assembly election. Previous studies on the effects of the MMM electoral system on the weakening of the regional hegemonic party system had methodological limitations, in that they superficially evaluated its institutional effect, using such criteria as the proportionality index. Unlike these previous studies, this research analyses the institutional effect of the MMM electoral system in a more sophisticated manner, holding constant the influence of effective regional political leaders, which may nullify the effect of the MMM electoral system as an omitted variable untreated by the previous studies. The panel analysis of this paper was able to reveal two crucial findings. Firstly, the MMM electoral system has a statistically significant effect on the alleviation of the regional hegemonic party system. Secondly, the presence of effective political leaders in the regions has a negative determinant effect on the mitigation of the regional hegemonic party system.