The Optimal Currency Area theory stresses the importance of co-movement of the business cycles of member states in order for the common currency to be successful. Yet, the identification of (European) business cycles has been inconclusive and is complicated by the enlargement to the new member states in 2004 and their transition to market economies. In this paper, we show how to decompose a business cycle into a time-frequency framework in a way that allows us to compare the growth rate spectra and coherences for the Hungarian, Polish, Czech, German and French economies. We find that, since joining the EU, there has been convergence on the euro area economy at short cycle lengths, but little convergence in long cycles. We argue that this shows evidence of nominal convergence, but little real convergence. The standard Maastricht convergence criteria for membership of the euro therefore need to be adapted to test for real convergence.

JEL Classification: C22, C29, C49, F43, O49

Keywords: Time-Frequency Analysis, Coherence, Growth Rates, Business Cycles