Berechnung des Xgen unter Verwendung von Regressionsmethoden

The “CPI-X” regulation allows a dynamic adjustment of the revenue cap. The general X factors is a correction term for the consumer price index (CPI), since the CPI does not represent the development of the efficient costs in the network sector. This article shows how the general X factor can be calculated using regression analysis and discusses its applicability in the German regulation context. The results show that the general X factor can be calculated using suitable panel methods, but also shows the practical limits of this approach: panel models often do not converge in short time series. In addition, regression analysis can only provide a prognosis for the future general X factor if stable economic and regulation conditions can be assumed. This is currently not the case in the German regulatory context.