日本首相解散眾議院之研究──「選舉制度改革」之影響與分析

The Study on Japanese Prime Minister’s Dissolution of the House of Representatives: Impact and Analysis of “Reform of the Electoral System”

首相握有解散眾議院的主動權，眾議院解散後，隨之而來的總選舉結果，往往導致執政黨內部權力結構的改變，甚至誘發日本政治版圖的變動。選舉時，選舉制度是將選票轉化為席次的遊戲規則，不同的選舉制度建構出不同的政黨體制。日本政府於1994年進行選舉制度改革，採用「小選舉區比例代表並立制」，新選舉制度實施後，政黨體制與政黨政治發生了變化。 以往對首相解散眾議院的研究，大多集中在自民黨單獨執政時期（五五年體制時期），較少論及選舉制度改革後的情形。本文擬從選舉制度改革對政黨政治的效應，來說明對首相行使眾議院解散權的影響，藉以補充既有得研究成果，同時掌握現代日本政治的變動。

The Prime Minister is granted the power to dissolve the House of Representatives. After the dissolution of the House of Representatives, the results of the general elections that follow often lead to changes in the power structure of the ruling party and even induce changes in the political landscape of Japan. In elections, the election system is a game that converts votes into seats. Different election systems construct different party systems. The Japanese government reformed the electoral system in 1994, adopting the“Mixed System of Single - Member and Proportional - Representation Districts.”After the implementation of the new electoral system, the party system and party politics changed. Previous studies on the Prime Minister’s dissolution of the House of Representatives have mostly focused on the period when the Liberal Democratic Party was in power alone (five-five-year system period), and less on the situations after the reform of the electoral system. This article intends to explain what effect the reform of the electoral system has on the Prime Minister's exercise of the right to dissolve the House of Representatives, which supplements the existing research results and helps insight into the changes in modern Japanese politics.