Why do parties split and merge in South Korea? 1

This study aims to inquire structural and institutional factors to induce repeated splits and mergers of Korean parties. The five-year single term presidency with multi-partism of Korea usually has vulnerable accountability and weak representativeness. Under this presidential system, the simultaneously strengthening “presidentialized government” and “partified government” also have accelerated splits and mergers of parties before and after the elections. The strong property of vote-seeking of Korean parties offered party members strong incentives to split or merge parties. The inherited factional party politics of Korea and weak vertical integration among party factions may have accelerated the splits of parties. These repeated splits and mergers of Korean parties delayed party institutionalization, and ultimately increased the vulnerability of the political system and undermined governability.