從德國選舉法修正論我國立委選制改革：聯立制的適用性

An Analysis of Taiwan’s Electoral Reform in Terms of German Electoral Law Amendment: The Applicability of Mixed Member Proportional System

我國立委選制自2008年採行並立式單一選區兩票制（以下簡稱「並立制」）以來，一直有檢討批判的聲音。社會各界批判的主要觀點認為，並立制造成各黨得票率與席次頗不吻合（即比例性偏差的現象），且扼殺小黨的生存空間，而主張以德國聯立制取代現行的並立制，甚至有批判者認為並立制違反自由民主憲政秩序而聲請釋憲。選制改革至今仍是政壇與學界熱列討論的議題，而其中核心的議題即是：就我國整體憲政運作而言，聯立制是否真的是比並立制更適切的選舉制度？事實上，德園聯立制實施至今，在德國國內也引起了許多爭議，例如當選基數、政黨門檻、選區劃分等爭議，而期中最重要的一項爭議，即是超額議席及所衛生的選票負面效力，而近年來德國聯邦憲法法院已兩度宣告聯邦選舉法的若干規定違憲，促使德國國會條法進行選制改革。德國選舉法修正採行了「平衡議席」機制，雖然矯正了超額議席的問題，卻導致計票程序更為複雜，普使國會總席次大幅增加，德國選制改革選得治絲益芬。就此看來德國聯立制在德國人的心目中並非完全無暇的選舉製度。本文以德國選舉法修正的前因後果為基礎，探討我國立委選制改為聯立制的妥適性，並分析當前社會各界對聯立制的普遍讚揚是否是一種迷思。本文認為，若將憲政體制與選舉制度進行配套思考，在我國當前半總統制的基本格局未大幅更動的情形下，立委選制採行聯立制並不見得是一個妥適的改革方向。若要改良我國當前的立委選制，以當前的並立制為基礎進行微調，或許較為妥適。

Ever since Taiwan’s adoption of a Mixed Member Majoritarian system (MMM) for its legislative elections in 2008, the disproportionality between the percentage of votes and actual seats, as well as the marginalization of smaller parties which has resulted from this shift, have been heavily criticized. Those opposing the system even petitioned for a constitutional interpretation which, they hoped, would find the MMM system to be in violation of liberal and democratic principles. Among the proposed solutions, a shift to a German-style Mixed Member Proportional system (MMP) has received the most attention. However, in framing the issue in terms of a clear-cut decision for either MMM or MMP, the debate about electoral reform in Taiwan lacks nuance. In particular, it tends to overlook the challenges which MMP has faced in Germany in the recent past. The problem of overhang seats and the connected problem of negative vote weights, in conjunction with changes in the party system, have all led to greater disproportionality. Bearing these in mind, this paper discusses the question of which electoral system best suits the needs of Taiwan, and concludes that the MMP system is not compatible with the current semi-presidential system of government. In short, it is rather more feasible to have minor reforms on the existing MMM system, instead of switching into the MMP one.