The DIW is the largest and oldest economics institute in Germany and conducts research in many fields of economic analysis. In this contribution to the conference celebrating the 80th birthday of this important institution I feel stimulated to address a few analytical issues, raising questions...

[...] in many situations a decision does not have to be made immediately, but can be delayed until additional information has been acquired. Sequential analysis seems particularly applicable to the problem of predicting turning points in the business cycle (Palash and Radecki, 1985). Elaborating...

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)....

In this paper, we investigate the impact of the adjustment for seasonal effects with different seasonal adjustment methods, the possible pre-treatment for calendar effects and the different order of aggregation and adjustment for the determination of the turning points of the European business...