Anatomy of a split: The liberal Democrats of Japan

This essay investigates the historic split of Japan's Liberal Democratic Party in the summer of 1993, when a substantial minority of LDP members defected to the newly-formed centrist parties Shinto Sakigake and Shinseito. Our primary theoretical inspiration in interpreting this split is drawn from the extensive literature on the stability of European coalition governments. We use this literature to inform both a narrative history of factional strategy at a macro level and a probit analysis of the determinants of defection at the micro level. Two other cases of LDP defection-the formation of the New Liberal Club in 1976 and the vote on electoral reform in November 1933-are also examined at the micro level. The analysis puts particular emphasis on anticipations of electoral consequences and trends as key factors in explaining both faction leaders' strategies and LDP members' decisions to defect.