日本首相解散眾議院之研究：「七條解散」慣例的形成與分析

The Study of the Japanese Prime Minister's Dissolution of the House of Representatives: The Formation and the Analysis of the 'Article 7 Dissolution'

政黨政治與政權運作一直是日本政治研究的焦點。大部分的研究是從眾議院選舉的結果，來論述政黨政治的變化，以及執政黨內部權力結構的改變，較少會追溯到首相解散眾議院的決定與影響。然而，眾議院的選舉，往往是因為首相解散眾議院後舉行的。現行憲法體制下，眾議院舉行過25次總選舉，其中24次便是解散後的選舉。在眾議院被解散的24次之中，有21次是首相直接根據憲法第7條行使解散權（七條解散）解散的。但是，吉田首相首次行使「七條解散」之際，因為憲法未有明文的規定，因而導致日本政壇發生重大的紛爭。然而，現今首相被認為可以行使「七條解散」的專屬權力，並得以自由行使。本研究的主要目的在於解釋首相行使「七條解散」的權力，在戰後的政治中，為何及如何形成政治上實踐的「慣例」。

Party politics and political power have always been the focus of Japanese political studies. Most of the research papers discuss the changes in party politics and the changes in the internal power structure of the ruling party based on the results of the House of Representatives elections; that is, not much research centers on the decision-making process and the influence of the Prime Minister's dissolution of the House of Representatives. However, many elections are held owing to the Prime Minister's dissolution of the House of Representatives. Under the current constitutional system, the House of Representatives has held a total of 25 elections, of which up to 24 are post-dissolution elections. Among the 24 dissolutions of the House of Representative s, 21 were announced directly by the Prime Minister under Article 7 of the Constitution (Article 7 dissolution). Yet, when the Prime Minister Yoshita first announced the ''Article 7 Dissolution'', there was a major dispute in Japanese politics because the Constitution did not have explicit provisions for this action. Despite the controversy, it is now generally considered that the exclusive power of ''Article 7 dissolution'' is conferred on the Prime Minister, who is thus free to exercise it. The main purpose of this study is to explain why and how the Prime Minister exercises ''Article 7 Dissolution'' power in post-war politics, making it a convention in political practice.