Revisions to the statistical data on GDP

When releasing the data on GDP in 1999 Q1, the Czech Statistical Office (CSO) also published retrospective changes in the statistical data since 1994. The revisions were necessitated by the requirements of the EU Statistical Office (Eurostat) for making international comparisons of economic performance in different countries. In addition to Eurostat´s methodological recommendations, the revisions took account of changes in indicators stemming from updated external data (e.g. in the area of foreign trade) and the results of revisions to the quarterly statistical statements for 1997 and 1998.

The adjustments to the GDP statistics include:

  • changes in the level of GDP and related changes in individual components of domestic demand in current prices;
  • adjustments to deflators in individual years and quarters;
  • changes to the GDP level in constant prices in individual years and quarters ensuing from the above changes;
  • transfer of the time series from the price level of 1994 to that of 1999;
  • changes in the distribution of annual GDP into individual quarters.

The GDP level in current prices has been increased by 2%n3% over the entire time series (1994 -1998). The CSO has made partial adjustments to the deflators in all the revised years. These changes have partially modified the resulting relationship between data in constant prices and in current prices, but have not brought any fundamental changes in the year-on-year trends, as is clearly shown in Chart 3 on GDP in constant prices using the original and revised figures.

More significant changes have been made to the quarterly data on GDP and domestic demand and their individual segments (inventories in particular). The revisions affected the first and fourth quarters mostly strongly, with consequent implications of the altered bases for year-on-year GDP comparisons in individual quarters (Chart 2). These comparisons served as the foundation for analyses in previous Inflation Reports. Compared to the previous CSO publications on GDP, the latest publication for 1999 Q1 also comprises a complete time series of data on GDP structure by sector in current and constant prices based on gross value added.

Chart 1 Original and revised data on GDP in current and constant prices
Chart 1

Chart 2 Changes in quarterly data on GDP (constant prices)
Chart 2

Chart 3 Changes in y-o-y GDP (constant prices)
Chart 3