Seasonal adjustment of IIP (Methodological note)

Sub-annual macroeconomic statistics today are a key tool for economic policymaking, business cycle analysis and forecasting. However, these statistics are often influenced by seasonal fluctuations as well as calendar and trending day effects, which can cover relevant short- and long-term movements of the time series and obscure a clear understanding of economic phenomena.

Hence, statistical indicators related to growth measurements are often characterized by
significant seasonal variations and differences in the number of working days over time periods under comparison. The Quarterly Index of Industrial Production (QIIP) is one of the most important industrial short-term indicators measuring the rise and fall of industrial output volume with a special focus on detecting the business cycle’s turning points as early as possible.

To obtain a meaningful comparison of growth rates for different periods within a given year and to better understand and interpret underlying trends UNIDO has been publishing growth figures based on seasonally adjusted index numbers. The index numbers are seasonally adjusted using the TRAMO/ SEATS method1 in the Demetra+ software.