歐洲聯盟於二○○二年三月一日起，正式啟動歐元（euro）在各會員國之間流通，使得各國各自的貨幣走入歷史。此一政策源自於經濟暨貨幣聯盟（Economic and Monetary Union, EMU）政策，對於歐盟各會員國而言，採行一致政策將可能放棄本身的利益和部分主權來促成，當然，這將有助於整合的最終目標－政治整合的建立。因為，EMU政策不僅牽涉到各會員國的經濟政策，更是各會員國本身在政治層面決策的一大突破。然而，是否所有會員國對於「經濟暨貨幣聯盟」政策沒有分歧的意見嗎？如果有分歧的話，「經濟暨貨幣聯盟」政策為何還能在歐盟間形成呢？各會員國的考量為何？各會國間對於彼此的態度為何？本文藉由社會選擇理論的研究途徑來分析各會員國的考量，以及EMU政策之所以成形的歷程。

　　　　　On the road to European Union integration, economic and monetary union is the principle policy. Why and how does the policy work inside individual EU member countries? How many dimensions would the countries evaluate when it comes to policy-making? Under unanimity rule, every member has to agree with and execute all the policies made by the EU. However, EMU policy concerns EU members' concessions to their own individual monetary sovereignty. Moreover, not all members agree with this policy, and some have publically rejected it. This policy is still working under its original schedule. Are there any special considerations caused by this lack of unanimity? This article analyzes EMU policy mainly through social choice theory and evaluates the final output of the EMU policy by illuminating member preferences.