EN
Critical appraisal of the optimum currency area theory, seen as the theoretical foundation of the monetary union, opens the article. The author points to the reserved attitude of the promoters of the European Monetary Union (EMU) towards the theory of optimum currency area as containing the justification for the adoption of common monetary unit. The history of existence of EMU provides empirical data that display marked divergencies in macroeconomic conditions among euro zone member countries. The observed divergencies are discussed in reference to the literature of the subject. Arguments that surround the theory of optimum currency area on the one hand and the divergencies among economies that belong to the EMU on the other, provoke to ask questions addressing the issue of how to explain the phenomena that reveal themselves in the euro zone. The concluding part of the article contains an attempt to answer the formulated questions. An original theoretical model is used to provide hypothetical explanations of the processes that take place inside the EMU.