Stability of multivariate representation of business cycles over time

In order to replace the univariate indicators standard in the literature (cp. [Opp96]) by a multivariate representation of business cycles, the relevant 'stylized facts' are to be identified which optimally characterize the development of business cycle phases. Based on statistical classification methods we found that, somewhat surprisingly, only two variables, 'wage and salary earners' and 'unit labor costs', are able to characterize the German business cycle not only the most stable over all sub-cycles but also with a quite reasonable error rate.