Seasonally adjustedindex of sold production of industry
Index of sold production of industry seasonally adjusted. Seasonal adjustment consists in elimination of the calendar variability effect and the variability of working days (changes of working time in succeeding months) and seasonality effect (annual, regular deviations from the trend, observed in annual cycle).
For seasonal adjustments, the JDEMETRA+ software and TRAMO/SEATS method is used- recommended by EUROSTAT.
The basis for seasonal adjustments is a long series (minimum 5 years) of production indices in constant prices. The need to ensure stability of results published requires using, at the calculations stage, fixed forecast parameters on annual periods. After such periods, the correction of data published is made.
GUS – Departament Przedsiębiorstw