The 1998 CPI Revision: Changes in Available Data Series
With release of the Consumer Price Index (CPI) data for
January 1998, the CPI will reflect several program improvements.
For example, the area sample will be updated to reflect the
population distribution from the 1990 (instead of 1980) Census.
This makes the CPI more useful because the samples it is based on
will better reflect where people now live and shop.
The CPI will also update the expenditure weights used in its
market baskets to represent 1993-95 (instead of 1982-84) spending
patterns. New expenditure weights improve the CPI because
consumers change their purchasing patterns in response to many
long-term factors. Without updates the index would overweight
many now infrequently purchased items, such as domestic service
and phonograph records, and underweight many newly important
items, such as adult day care and computer software. In addition,
the CPI will, for the first time, use estimates of index
variances as a guideline for determining which data series will
As a result of the improvements, the list of items and areas for
which CPI data will be available will change. Some of the most
significant changes include:
Effective with the release of the January 1998 Consumer Price
Index (CPI) data in February 1998, the list of items and areas
published will change, namely:
- Some areas will change publication cycles.
- Many area definitions will change.
- There will be eight major groups instead of seven, and
the content of some of the groups will change.
- Item categories, definitions, and publication levels will
|'If you have a contract tied to a
local area or an index series other than
"All Items," you will want to see if
the contract remains valid.
Although the CPI is a measure of price change for a fixed
market basket of goods and services bought by consumers,
periodically BLS updates the goods and services for which prices
are collected, so the CPI will continue to accurately represent
what consumers are buying. In addition, changes in the population
size of various cities and regions must be taken into account in
the CPI structure, so the CPI will accurately reflect the current
population distribution. These periodic adjustments are called
"major revisions." There have been five previous major
revisions to the CPI, and another is scheduled for January 1998.
This fact sheet highlights the most important changes associated
with the 1998 CPI Revision and lists additional sources of
information about this revision.
Area publication cycle changes
Baltimore and Washington will be combined
into one metropolitan area and will be published on a bimonthly
basis for odd (January, March, etc.) months. After December 1997,
separate CPI's will not be published for either Washington or
Philadelphia and San Francisco, two areas that
are now published monthly, will be changed to a bimonthly basis
for even (February, April, etc.) months.
Buffalo and New Orleans will no longer be
Pittsburgh and St. Louis will change from
bimonthly to semiannual publication. (Semiannual indexes
represent the index for the firstor secondhalf of the
year and do not represent any single month.)
Seattle and Atlanta will
increase their frequency from semiannual to bimonthly for even
(February, April, etc.) months and Tampa will
increase its frequency from annual to semiannual.
There will be a reduction of city-size classes from four to
three. The A population size will represent all metropolitan
areas over 1.5 million (plus Anchorage and Honolulu); B/C will
represent smaller metropolitan areas (1.5 million or less); and
D, all nonmetropolitan urban areas.
Area definition changes
Many of the areas will be redefined, based on the new Office
of Management and Budget (OMB) metropolitan area definitions.
These changes are hinted at by some of the changes in area
titles. For example, the Detroit-Ann Arbor, MI area will be
retitled the Detroit-Ann Arbor-Flint, MI area. (For more details,
see the list of definition changes for published metropolitan
Major group structure and content changes
There will be eight major groups instead of seven, and the
content of most groups will change. (For more details see the
list entitled Highlights of the CPI Item Structure Changes by
Major Group and Main Housing Subgroups.)
Changes in the level of detail published
In addition to changes in area and item definitions, there
will be some reduction in the number of detailed indexes
available (especially below the U.S. city average level), due to
limitations in sample size.
For more information
BLS has more detailed information available on the 1998 CPI
Revision. For example, reprints of the December 1996 Monthly
Labor Review articles on the CPI revision are available upon
request. For these, or other additional information about the
CPI, please contact any of the eight BLS regional offices
(located in Boston, New York, Philadelphia, Atlanta, Chicago,
Dallas, Kansas City, and San Francisco); call our national
information staff at (202) 691-7000; or write to:
Bureau of Labor Statistics
Division of Consumer Prices and Price Indexes
Room 3615 PSB
2 Massachusetts Ave., NE
Washington, D.C. 20212-0001
Internet address: http://www.bls.gov/cpi/
Information in this report is in the public domain, and with
appropriate credit, may be used without permission. This
information is available to sensory impaired individuals upon
request. Voice phone: (202) 691-5200; Federal Relay Service:1-800-877-8339.
Last Modified Date: October 16, 2001