EN
The objective of the paper is to present some arguments stemming from economic theories which tend to be overlooked in the debate on adoption of the common currency. The paper focuses on the issues of welfare and efficiency. In particular, the article is devoted to an analysis of the origins of transaction costs, the role of stabilization policies, market completeness and informational issues in the process of the determination of the optimal currency system. The paper shows that insights gained from economic theory on the issue of the adoption of euro as a common currency can in a meaningful and interesting manner complement the so far known results.