Seite - 122 - in The Austrian Business Cycle in the European Context

122 length. This is the case for the reference series, the German manu- facturing production gerCDE and the euro area GDP (eurGDPex). Again, no systematic change of the cycle length shows up when idiosyncratic parts of the series are extracted. For BK-filtered data, the extraction and dating of the common component did not lead to a substantial change in the length of cycles or phases. The reduced number of turning points in the common component of the reference series led to cycles becom- ing longer by around 3 quarters. Especially the phases of downturn (from a peak to a trough) are extended (+3 quarters), whereas for upturns only one quarter was added. For the rest of the BK-filtered data, the picture hardly changed. In many cases, the cycle and phase lengths did not change at all. This leads to the conclusion that for the underlying data set idio- syncratic cycles are mainly a phenomenon outside the business cycle frequency band. In that case, the extraction of idiosyncratic cycles does not lead to a change in the dating calendar, but rather the different amplitude of just filtered series and common components changes the pattern of local minima and maxima. 8.3.2.1 Conclusions for the dynamic-factor-model-determined reference cycle approach Before comparing all findings with those of other studies on the Austrian business cycle, results from this chapter are summarised. As expected, the fact that the first-order-difference filter superim- poses high-frequency variations leads to a rather erratic output of the filtered series. Visual inspection does not reveal any regularity of business cycle variations. Cross-correlation statistics between the reference series and all other series are lowest for first-order dif- ference, as included superimposed high-frequency cycles seem to be of idiosyncratic nature. The same goes for cross-correlations of common components extracted by the dynamic factor model approach. As a consequence, all other statistics checking for