Producer Price Indices - Basic Information
Introductory note | Contents |
Released since 2001 have been price indices calculated according to new revised index patterns, which are based on the structure of 1999.
The weight systems and samples of price representatives and reporting units (respondents) were revised in the framework of a comprehensive revision, which was run for individual price areas during 2000. The weights were determined on the basis of sales ( revenues) for 1999.
At the same time, the basic period was changed. It is now December 1999 (or 1999 average) for new indices released since 2001. The average of 2000 was introduced for all price indices as a standard index reference period, which is calculated in a derived way from the constant base December 1999 like other price bases.
The price indices are calculated for prices of samples of representatives and for selected reporting units by aggregating simple price indices into an aggregate using a modified Laspeyers formula. The calculation uses 1999 constant weights.
p1 = the reference period price,
p0 = the basic period price,
p0q0 = the constant weight: value indicator, usually in terms of per mill (sales, 1999 revenues).
A detailed breakdown of the aggregate indices is given in separate publications, including methodological notes, which are available as a rule on the 25th calendar day following the reference period.
Continuation of the time series published before 2001 and still valid and of the revised indices released since January 2001 is ensured by using coefficients (conversion bridges) calculated from the ratio of revised December 2000/December 1999 indices to original December 2000/December 1999 indices. The converted time series of the indices of individual price groups for previous years are released by the CZSO in the publication Revision 2000.