SEASONAL ADJUSTMENT OF CPI FOR MILLING AND BAKING PRODUCTS MONTHLY EVOLUTION AS AGAINST DECEMBER PREVIOUS YEAR IN ROMANIA – COMPARISON BETWEEN JDEMETRA+ 2.2.4 AND JDEMETRA+ 3.0.0

Abstract

In the present context, the consumption and saving patterns are subjected to change both locally and worldwide. The evidence on consumption reveals the importance of data handling and processing using the most relevant tools available. This research paper looks into official statistics data of Consumer Price Indexes (CPI) for milling and baking products and is based on seasonal adjustment. As such, JDemetra+ software is selected as officially recommended by Eurostat for seasonal adjustment. First section presents the official software recommended by Eurostat for seasonal adjustment, while section two discusses the characteristics and functionalities of the software. Furthermore, the following section presents the selected seasonal adjustment technique and describes the usage of monthly data. Section four analysing the results of all the seasonality tests for the selected series is followed next by a brief concluding remarks and observations section. Moreover, in terms of the conducted analysis, the paper examines to test JDemetra+ 3.0.0 pre-release version against JDemetra+ 2.2.4. Evidence favouring JDemetra+ 2.2.4 is obtained, the results showing that some new strategies might be needed in order to obtain better results on seasonal adjustment process using TRAMO-SEATS in JDemetra+ 3.0.0. Seasonal adjustment practitioners in official statistics should be aware and recognize the impact of statistical package selection. In this respect, optimal selection of analysis procedures is needed in the evaluation of a series and thus migrating from JDemetra+ 2.2.4 to JDemetra+ 3.0.0 is problematic without employing resources in developing appropriate strategies for improvement of the obtained results.

Keywords

• seasonal adjustment
• jdemetra+
• romania
• business cycles