Separating seasonal components from other sources of economic fluctuations is crucial for both economic modeling and policy making. Practitioners treat seasonality as noise to be removed before estimating models and tend to apply deseasonalizing methods i

This paper was commissioned by DG ECFIN from the EU Commission as part of the "EMU@10" project and is published in Hungarian language by the permission of the EU Commission. The original English language version of the paper is available at:...