With the release of data for January 2004, the Producer Price Index program changed its basis for industry classification from the 1987 Standard Industrial Classification (SIC) system to the North American Industry Classification System (NAICS). Developed in cooperation with Canada and Mexico, NAICS represents one of the most profound changes for statistical programs focusing on emerging economic activities. The system was developed using a production-oriented conceptual framework, grouping establishments into industries based on the activity in which they are primarily engaged.
While many NAICS industries directly compare with SIC industries, a number of SIC industries were split or combined to form a new NAICS industry. The PPI treats the SIC-to-NAIC comparison as continuous if 80 percent or more of the weight of the SIC-based index comprises at least 80 percent of the weight of the NAICS-based index. All index series that have passed this test are published under the NAICS structure using the index base date and price index history established by the SIC-based index.
Last Modified Date: March 24, 2004