1990年代後日本政治改革與自民黨派閥變動

Abstract

戰後日本政黨政治的發展，大致上以自民黨一黨獨大的「五五年體制」(1955-1993) 為主軸開展。在五五年體制之下，日本經濟高度成長，同時卻也造成諸如「鐵三角」、「恩庇侍從」和「社會網絡」等「非正式制度」結構關係的出現，使得「利益誘導型政治」與「自民黨派閥政治」興盛。因而日本政壇於1990年代初期起，開始一連串的「政治改革」，對於自民黨固有派閥勢力帶來衝擊。本研究旨在透過「歷史制度論」的研究途徑，並結合過往文獻和相關數值資料，透過政治改革前後「選舉策略變動」、「派閥勢力變動」與「政治資金變動」等三種層面，藉以探討日本自1990年代之後，幾次重大政治改革的實施 (主要著眼於1994年細川內閣的政治改革，以及2000年至2007年間，四度對於《政治資金規正法》內容的修訂)，與「自民黨派閥」變動之間關係。

本研究的主要發現有三：首先，在「選舉策略變動」層面，自民黨在新選制下，主要採取「重複提名制 (搭配惜敗率)」、「與小黨共組聯合政權」等方式，以求能提高在國會選舉中可獲得總席次數。而自民黨相較政治改革前有「集權化」的傾向，同時擁有較大的政策主導權。因而使得政黨能力大增，對於既有派閥勢力則造成衝擊。其次，在「派閥勢力變動」層面，眾議院方面，自民黨派閥與候選人、眾議員之間連結逐漸薄弱化。內閣方面，未必需要「派閥背景」才能入閣，無派閥者 (甚至民間人士) 亦有機會擔任重要內閣職位。反映自民黨派閥重要性和影響力皆大不如前的事實。最後，在「政治資金變動」層面，捐款已經不再是自民黨堅實的收入來源，但自民黨派閥在2014年至2018年間的收入卻不減反增。自民黨亦逐漸加深對「政黨補助款」的依賴，顯示其政治資金的集資能力，遭到相當程度限縮，而必須仰賴新興財源。而自民黨派閥勢力所受到衝擊，則不如政黨整體。

The post-World War II development of Japanese party politics was mainly carried out on the basis of the 1955-system (1955-1993) of the Liberal Democratic Party (LDP)’s one-party dominance. Under the 1955-system, Japan’s economy has grown rapidly, but at the same time, it has also caused the emergence of informal institutions such as “Iron Triangle”, “Patron-Clientelism” and “Social Network”, which has led to “Interest-driven Politics (Pork Barrel)” and “LDP Factional Politics” flourished. Therefore, the Japanese political arena started a series of “political reforms” in the early 1990s, making a great impact on LDP’s factional structure. Through the approach of “Historical Institutionalism” and from the perspectives of “changes of election strategies”, “changes of the LDP’s factions’ power” and “changes of political funds” before and after the political reforms, this research aims to discuss the relation between several major political reforms in Japan since the 1990s (mainly focusing on the political reforms of the Hosokawa Cabinet in 1994 and four-time modifications to the Political Funds Control Act from 2000 to 2007) and changes of the long-lasting LDP’s factions by using both past literature and numerical data. There are mainly three findings in this research: Firstly, from the perspective of “changes of election strategies”, the LDP chiefly adopts strategies such as “dual candidacy (along with best-loser provisions)” and “forming coalition governments with small political parties” to maximize its number of seats in the National Diet under the new electoral system. The LDP also has an inclination of being more “centralized” and with greater policy-decision dominance. As a result, the capacity of the LDP is greatly increased, which has a strong impact on its factions. Secondly, from the perspective of “changes of the LDP ’s factions’ power”, the link between the LDP’s factions and the candidates or representatives has gradually weakened in the House of Representatives. And in the Cabinet, it is unnecessary for a cabinet member to have a “factional background”. Representatives who belong to no faction (or even non-politicians) still have a chance to take office of important cabinet positions, revealing the fact that the LDP ’s factions have become less important and influential than the past. Lastly, from the perspective of “changes of political funds”, donations are no longer a solid source of income for the LDP, but the income of the LDP’s factions has not decreased but increased between 2014 and 2018. The LDP also has gradually deepened its dependence on “political party subsides”, showing that its ability to raise political funds has been severely curtailed and must rely on new sources of income. However, the influence on the LDP’s factions is not as great as that of the political party as a whole.