Most of the Euro-zone economic short-term indicators are computed through aggregation from Member States data. The seasonally adjusted figures can be calculated by seasonally adjusting the aggregate (direct approach) or aggregating the seasonally adjusted national data (indirect approach)....

The purpose of this work consists in evaluating changes in the quality performances of two different and widely used programs for seasonal adjustment, X-12-Regarima and Tramo-Seats, when the length of time series is progressively reduced. The comparisons are carried-out by using appropriate and...