Avoiding a Two-Party System: The Liberal Democratic Party versus Duverger’s Law Steven R. Reed and Kay Shimizu In 1994 Japan enacted a new electoral system featuring single-member districts (SMDs). Though the new system includes a proportional representation (PR) tier, many reformers hoped it would lead to a two-party system. This points to Duverger’s Law, one of the most powerful generalizations yet produced by political science (Duverger 1964; Riker 1986). Duverger’s Law states that SMDs lead to a two-party system, and, in fact, Japan has moved closer to a two-party system in every election since the first under the new system, in 1996 (Reed 2007). Japan virtually has a two-party system in three important senses. First, in most districts, competition is between two—and only two—viable candi- dates, offering voters a choice between one candidate from the ruling gov- ernment coalition and one from the opposition. Second, in the 2005 general election, Japan’s two major parties together won 55.6 percent of the vote, a higher figure than Great Britain’s Labour and Conservative parties captured in the same year. Third, there is only one alternative to the Liberal Democratic Party (LDP), and that is the Democratic Party of Japan (DPJ). If the LDP were to lose, it would mean a DPJ government. That fact was confirmed by the LDP’s losses and the DPJ’s gains in the 2007 House of Councillors elections. The two parties now face each other across the Diet building, one ensconced in the Lower House and the other in the Upper House. But Japan has yet to experi- ence the defining characteristic of truly competitive two-party dynamics: an alternation in power between the parties. It is interesting to note that Italy ad- opted something similar to Japan’s new SMD system at almost the same time, and Duverger’s Law has worked much faster there (Reed 2001). Italy has seen three alternations in power in three elections, whereas Japan has experienced none in four elections. What explains the difference? Source: Reed, Steven R. and Kay Shimizu, “Avoiding a Two-Party System: The Liberal Democratic Party Versus Duverger’s Law,” in Steven R. Reed, Kenneth Mori McElwain and Kay Shimizu (eds.), Political Change in Japan: Electoral Behavior, Party Realignment, and the Koizumi Reforms, Stanford, CA: The Walter H. Shorenstein Asia-Pacific Research Center, 2009, pp. 29–46. Reprinted with permission of The Walter H. Shorenstein Asia-Pacific Research Center. © koninklijke brill nv, leiden, 2018 | doi:10.1163/9789004380554_054 Avoiding a Two-Party System 1321 The biggest political difference between Japan and Italy since the 1990s is that the predominant party in Italy, the Christian Democrats, disintegrated fol- lowing electoral rule change, while the predominant party in Japan, the LDP, remained intact. In Italy both the left and right have been engaged in the dif- ficult process of constructing new parties from the rubble of the old, but in Japan only the left is undergoing this process. The LDP experienced a serious split in 2005 and numerous tribulations in its attempts to adjust to the new system and more competitive environment, but it has managed to maintain a continuous organizational coherence—a strategic advantage over the opposi- tion. The party has expended great effort and displayed exceptional ingenuity in avoiding the outcome of a true two-party system: losing power. Historically, the LDP has displayed an impressive resourcefulness whenever it has faced a threat to its hold on power. When it was founded in 1955, the party seemed determined to revise the constitution, delete the peace clause, and rearm Japan. When that proved politically disastrous, the party reinvent- ed itself in the early 1960s as the party of economic growth. When economic growth came into conflict with environmental protection and pollution con- trol and the LDP lost control of urban local governments, it reinvented itself again, this time as an environmentally responsible party in the 1970 “Pollution Diet” (McKean 1981). A series of corruption scandals and failure to enact politi- cal reform resulted in the party’s first experience of opposition, in 1993, but the LDP managed to find its way back into power by allying itself with its historic enemy, the Japan Socialist Party (JSP). We must consider the possibility that the LDP will reinvent itself yet again and find a way to bypass Duverger’s Law. Under the new electoral system, the LDP has used three main stratagems to avoid the implications of Duverger’s Law. First, the LDP has been very creative in its use of the PR tier to elect two candidates from the same SMD. The logic of Duverger’s Law is based on the fundamental fact that only one candidate can be elected from a district. Under these circumstances, third parties have little chance of winning seats and any candidate who wants to win is virtually forced to choose between the two main parties. The LDP has used the PR tier of the current system to keep candidates who cannot be nominated in an SMD from defecting to the opposition. Second, the LDP has expended an incredible amount of ingenuity and en- ergy in its attempt to get and maintain the electoral cooperation of its coalition partner, the religious party Komei. To obtain Komei votes in the SMDs, the LDP directs its supporters to vote for Komei in the PR tier. Komei has a solid sup- port base but would be devastated by bipolar competition in the SMDs, coming in third at best and winning no SMD seats. Komei has SMD votes it can direct .