Investigating the seasonal structure in the German economy using fractional integration with structural breaks

Purpose – The purpose of the paper is to examine the seasonal structure in the German monetary aggregate M 1 and output by means of fractional integration techniques. Design/methodology/approach – The authors use a version of the tests of Robinson that permits testing seasonal I (d) models with the possibility of incorporating seasonal dummy variables and structural breaks. Findings – The results show that there is a strong degree of persistence in their behaviour, especially at the long run or zero frequency, with orders of integration ranging between 1.25 and 1.50. Originality/value – The main innovation in this work is the use of a new time series approach to the case of seasonality.