The convergence and the single currency - national and regional perspective: Causes the common currency convergence?

In the past two decades, the process of integration among the EU countries is still accelerating. With the onset of the global economic crisis emerged on the surface problems of the single currency, which to a large portion of the public seem to be fundamental. This work analyzes the single European currency; the author seeks an objective analysis of the benefits/costs of the single currency, i.e. euro. In the theoretical part, euro area is discussed as a single/optimum currency area. In the practical part of this work economic convergence of EU countries is analyzed. It's done before the introduction of the euro and after its introduction. Convergence is further examined at the level of individual EU regions (NUTS II). The aim is to show whether the introduction of a single currency for EU countries contributed more to accelerate economic growth and convergence of economics of single countries, or rather to their divergence.