Seasonal Adjustment of Time Series and Calendar Influence on Economic Activity
seasonal adjustment, working-day effect, leap year effect, Easter effect, calendar effects, JDemetra+
This paper describes the process of the seasonal adjustment of data time series for Croatia, a process that involves cooperation between the Croatian National Bank and the Croatian Bureau of Statistics. The paper shows individual steps of the process, explains calendar effects, describes the revision policy for seasonally adjusted data and presents the seasonal adjustment of selected main monthly indicators of economic activity in the Republic of Croatia: industrial production, the volume of construction works and retail trade turnover. Working-day effect was identified for all indicators; leap year effect was identified for all but the volume of construction works, i.e. the Easter effect for retail trade turnover only. The described assumptions and limitations of the models applied are useful to end-users for the purpose of a better understanding of the published data and their use in further analysis.