Changes In The Reform Of The Electoral System And Party System In Contemporary Japan

After the Second World War, competitive electoral system and dominant one-party system have co-existed in Japanese politics for a long time. With the disintegration of this political party system in 1993, Japan launched reforms in electoral system. In March 1994, the mid-size constituency system was changed into a mixed electoral system, combining single-member districts and proportional representative system, which was approved by Japanese National parliament (Diet). Therefore, the party system went into a new stage of development. From the changes in the political system, we can see specific and dramatic characteristics in the formation and breakdown of "1955 system". The unique performance indicates that the Japanese political party system has some distinctive aspects deserving further research.The available studies on Japanese party politics are mostly from the views of cultural traditions, social structure and party's development trend. Nevertheless, it surely indicates that the old and new political party systems in Japan are closely related with the electoral system if we study the formation and breakdown of "1955 system" and modern competitive electoral system. So, through the combination of institutional approach and theory of rational choice, this dissertation will explore the change of the Japanese party system from the perspective of electoral system. By doing so, we can enrich the theoretic framework of comparative politics and discover the distinctive Japanese party system.Chapter one is an introduction. The author will explain the origin and significance of the choice of topic and review the literatures on this topic. The author will conclude that there are three different approaches to the studies of political party system, and will bring forward his own approach and research method. He will analyze the basis, ideas, theories and realistic meanings of studying party politics from the perspective of electoral system.The formation of mid-size constituency system and "1955 system" will be discussed in chapter two. It will discuss the formation process of mid-size constituency system, as well as the formation process and causes of "1955 system". The author will bring forward in this chapter that the history of Japanese electoral system is in fact a cycle of single-memberconstituency, mid-size constituency and big-size constituency. By investigating the choice of mid-size constituency twice in the history, we can find that the final choice of mid-size constituency is largely the result of three big parties repulsing small parties. But mid-size constituency is an electoral system that encourages the co-existence of multiple parties. So the mid-size constituency has led to a multi-party system. Once the LDP and the SP became big parties through merging respectively, the encouraging function of mid-size constituency has changed and becomes helpful to the solidification of the existing big party system after 1955.In chapter three, the crisis of mid-size constituency system and "1955 system" will be studied. Author will discuss the impact force on the original system caused by the change of Japanese social economic structure, the obstacles all parties have met during their transformation, and the disadvantages caused by LDP's long-term one-party rule. As the Mid-size constituency was not the cause of the formation of the "1955 system", it was not the cause of the breakdown of the "1955 system". The crisis of the "1955 system" is due to the change of the social structure and constituency structure. However, the Mid-size constituency system is a retarding force for the parties' reform.In Chapter four the causes and process of the electoral reforms will be discussed. Some basic theories of electoral system reforms in terms of aim and approach, the background and process of the introduction of new electoral system under the "1955 system" will be analyzed. Resistance and opportunities for new electoral system reform, and comparison between new and old electoral systems will be also discussed.Chapter five will discuss the impact of new electoral system on the party system. Through the analysis of several general elections after electoral system reform, the combination and disintegration of parties during the elections, the author studies the impact of new electoral system on the party system.Chapter 6 is the conclusion. The author will make a general explanation and comment on Japanese electoral system reform, including causes for changes in electoral system and party system, impact of electoral system reform on party politics. Through international comparison, the author will put forward some of his own basic ideas in terms of comprehensive impact on electoral system reform in Japan. The changes and developmentof party system under mid-size constituency system show a complicated relationship between political system, social structure, and political choice. The same mid-size constituency system has played different roles in different political development stages in Japan. The choice of a political system is decided by a series of factors. The choice and establishment of a new system is not at all a rational process. At the same time, the same system may play different roles under different circumstances. So the new electoral system may lead to different party systems in Japan. The reforms are more successful at the operational level than the political structure level.