Mathematical statistical method
Since the end of 2017, seasonal adjustment at the Federal Statistical Office has gradually changed over to the X13 procedure in JDemetra+. The mathematical statistical method X13 does not differ fundamentally from the previously used X-12-ARIMA procedure.
For an application-oriented description of the procedures please see Wirtschaft und Statistik 4/2018.
Software
Seasonal adjustment according to X13 is carried out with the program JDemetra+, a platform-independent open source software developed by Eurostat which has been recommended for seasonal adjustment of official statistics within the European Union. For seasonal adjustment according to X-12-ARIMA a software of the U.S. Bureau of the Census with the same name is used.