Each year, two days prior to the release of January data, the Bureau of Labor Statistics (BLS) publishes new seasonal factors for the Producer Price Index (PPI) that reflect price movement patterns for the just-completed calendar year. The new factors are applied to commodity indexes for the previous five-year period. It was recently discovered that an error in this annual process occurred in 2008 and affected the seasonally factors and seasonally adjusted monthly indexes values for three commodity series for 2003-2007. The three series, first posted on February 22, 2008, remained incorrect on the commodity seasonal factor listing and in the Labstat database through May 20, 2008. On that date, an updated seasonal factor listing was posted to the PPI website and corrected values were posted to Labstat and marked with an r flag. The affected indexes are listed below.
|Series ID number||Index title|
|WPS026||Beverages and beverage materials|
|WPS141||Motor vehicles and equipment|
Seasonally unadjusted index series were not affected by this processing error. BLS regrets any inconvenience this error may have caused data users. Further information is available from the PPI Section of Index Analysis and Public Information at (202) 691-7705.
Last Modified Date: May 20, 2008