Quarterly National Accounts of the Czech Republic
Introductory note | Contents |
The publication presents quarterly estimates of GDP and other indicators of national accounts at current prices, at previous year average prices and at constant prices of 1995 (obtained by chain-linking) for the period of the first quarter of 2003 to the fourth quarter of 2004. The data are both raw and seasonally adjusted (including the correction of a different number of working days in individual periods).
In comparison with the data published on 10 December 2004, the preliminary GDP growth estimates of the three preceding quarters were revised. The growth estimate of the Q1 2004 (+3,5%) has been updated to 3.8%, while that for Q2 2004 (+3.9%) and Q3 2004 (+3.6%) identically to 4.0%. The indicators were revised with respect to updated data from quarterly statistical surveys processing of February 2005 and updated quarterly balances of payment. The quarterly estimates for 2003 have not been changed.
Available for users at the website http://www.czso.cz/csu/czso/gdp_national_accounts_ekon are quarterly time series of GDP expenditures and gross value added by the kind of activity (including indices and deflators) for the period from the first quarter of 1995 to the fourth quarter of 2004.
The publication also shows quarterly accounts for the households sector for the period of the first quarter of 2003 to the fourth quarter of 2004 at current prices, not seasonally adjusted.
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The methodology of converting quarterly national accounts data from current prices into constant prices was harmonized with the procedure used in annual national accounts. Unlike the concept used before for converting the time series into base year prices (so far 1995 in the CR), another approach is taken. As a rule, the indicators are converted at first into the previous year’s average prices (the previous year is always the basic year, the base is changed for every year). Year-on-year index is so independent on the choice of reference year (1995 year in our case) and is far less biased by the gradual out-of-dating of the chosen basic year’s weights. The chain-linking of data at the previous year’s average prices into reference year prices is provided by means of annual average price indices. The publication includes the data at current prices, at previous year’s average prices and at constant prices of 1995. The time series at 1995 constant prices were obtained by chain-linking y-o-y indices of physical volume.
a) Comments to the data at the previous year’s average prices:
These data were obtained from the data at current prices by deflating with the price indices “the previous year’s average = 100”. It follows that price bases in individual years differ and quarterly data are comparable only in the frame of one year. Aggregates are additive, they are obtained as sums of appropriate individual items at the previous year’s average prices. E.g. the total final consumption expenditure at the previous year’s average prices is equal to household final consumption expenditure + government institutions final consumption expenditure + NPISH final consumption expenditure that were separately deflated by various methods into the previous year’s average prices.
b) Comments to the data at the constant prices of 1995:
These data were obtained by chain-linking from the data at the previous year’s average prices. The chain-linking includes compiling long-term price indices and volume indices by means of the same short-term characteristics based on different and actual weights. E.g., the volume index of the particular indicator between 2004 and 1995 years is calculated as a product of individual year-on-year volume indices for the whole period 1995-2004. As a result of using this method of chain-linking (annual overlap technique which is one of methods recommended by Eurostat) aggregates are not additive. It means that values of aggregates at constant prices do not agree with sums of individual components at the same constant prices.
When estimating GDP levels for the first and second quarters of 2004 (in June and September 2004), however, we chain-linked only individual indicators and GDP. Subtotals (e.g. final consumption expenditure in total) we obtained as the sum of individual chain-linked components (expenditures by households, general government and non-profit institutions in this case). After the consultations with OECD experts we stopped using this approach and each aggregated indicator (on every aggregation level) is chain-linked separately. This also applies to value added which arises as the difference between output and intermediate consumption at both current and previous year’s prices
Methodological note on seasonal adjustment:
The publication includes current price and 1995 constant price values of GDP and GDP components, as they were produced and used, which are adjusted for seasonal variation. The seasonal adjustment is carried out with the help of the TRAMO/SEATS method, which consists in decomposing the time series into trend, cyclical, seasonal and irregular components. The seasonal component is excluded and the remaining three are put together to make up a seasonally adjusted time series. The seasonally adjusted time series are retrospectively recalculated every quarter with regard to extension and revision of the original, non-adjusted time series. For the first time, a correction for a number of working days in individual periods was performed on selected time series in which the influence of different numbers of working days is significant statistically. Since a number of working days influences annual figures, too, annual totals of seasonally adjusted values do not correspond to those of the original, non-adjusted values in the series.
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GDP estimate for the first quarter of 2005 is to be released on 9 June 2005 consistently with the time schedule of national accounts releases which is situated at the CZSO web site http://www.czso.cz/eng/redakce.nsf/i/deadlines_for_the_national_accounts_releases_in_2005