台灣與蒙古同屬第三波民主化下後列寧群集之新興半總統制國家，兩國同處亞洲、民主化時間相近、長期有相鄰強國的威脅，今日亦同時被美國自由之家評比為「完全自由」的國家。不過，兩國採用半總統制後有不同的政府型態與憲政運作：第一，蒙古在總統與國會不一致時歷經數次「共治」，而同樣的情況下台灣則出現「國會有多數的少數政府」與「國會無多數的少數政府」，本文認為原因包括憲法上總理產生是否需國會同意之規定、總統是否有將總理主動免職的規定、倒閣與解散權的配套設計、選舉花費、在野黨席次增減與選舉恩怨、國會議員選制、在野黨掌握國會多數席次比例的程度、民意支持等。第二，蒙古在2004年國會選舉結果兩大黨席次都接近半數時，組成了兩大黨聯合的「一致多數政府」，而台灣在國會選舉結果兩大黨席次近半數時卻沒有產生這樣的政府，本文認為原因則包括一國社會是否有重大社會分歧與危機、菁英是否有妥協的政治文化、政黨體系與光譜、憲法上關於獨立候選人參與組閣之規定、憲政慣例等。本文並提出總統與國會不一致之下，解釋四種政府型態出現的一般性成因。最後，本文從台灣與蒙古政府型態與憲政運作之比較提出兩國民主發展可互相參考之處。

Taiwan and Mongolia are both belong to newly post-Leninist semi-presidential countries. Both countries also are located in Asia, been evaluated as “free” by Freedom House, and have strong neighbors and democratized at almost the same period. However, these two countries have different government types. First, Mongolia has experienced “cohabitation” under incongruence of president and parliament, but Taiwan has experienced “minority government with parliament majority” and “minority government without parliament majority.” Second, Mongolia has experienced coalition government as “united majority government” by two major parties while Taiwan has not.This paper tries to explain these two questions by many institutional and non-institutional factors.

半總統制;共治

Semi-presidentialism;cohabitation