Overview of the 1998 revision of the Consumer Price Index
The current revision of the Consumer Price Index
encompasses changes ranging from reselecting areas, items, and
outlets, to new systems for data collecting and processing
The Consumer Price
Index (CPI) is the principal source of information concerning
trends in consumer prices and inflation in the United States, and
is one of the Nations most important economic indicators.
The measure is used extensively for economic analysis and policy
formulation in both the public and private sectors, and for
escalation of contract amounts and other payments among
individuals and organizations. The CPI also has a significant
impact on the finances of the Federal Government. It is used to
adjust payments to Social Security recipients, to Federal and
military retirees, and for a number of entitlement programs such
as food stamps and school lunches. An increase in the CPI
increases Federal statutory obligations for these payments and
programs. In addition, individual income tax brackets and
personal exemptions are adjusted for inflation using the CPI. In
this case, an increase in the CPI results in lower tax revenues.
It is estimated, for example, that in fiscal year 1996, each
1-percent increase in the index produced a $5.7 billion increase
in outlays and a $2.5 billion decline in revenues.1
To maintain the
accuracy of the CPI, an updating of the index is undertaken
approximately every 10 years. The most fundamental and visible
activity in each of these CPI revisions is the introduction of a
new "market basket," or set of expenditure weights
attached to the categories of goods and services comprising the
CPI. Because the next market basket introduction will occur in
January 1998, the current revision effort is usually identified
as the 1998 CPI revision. Revisions of the CPI are comprehensive,
multiyear efforts, however, and the current revision is planned
to be completed over a 6-year period ending in 2000. The projects
and changes encompassed in the current revisionthe sixth
major revision in the CPIs historyrange from the
reselection and reclassification of areas, items, and outlets, to
the development of new systems for data collection and
processing. This article provides a general description of those
projects and changes, and directs the reader to additional
articles in this issue for more in-depth treatment of several
topics.
About revisions
Context. The CPI is a measure of price
change for a fixed market basket of goods and services of
constant quantity and quality purchased for consumption.2 Consumers change their purchasing
patterns in response to a myriad of factors, including relative
price changes, real income changes, the introduction of new
product distribution patterns and marketing techniques,
population and other demographic changes, and changes in consumer
preferences. The CPI samples and weights are updated during
revisions to reflect these marketplace changes, because without
such updates the index would cease to be an accurate measure of
current price inflation. The technological improvements
undertaken during CPI revisions also contribute to improved
accuracy by making possible more and faster data collection, with
fewer errors.
It is important to
note, however, that numerous methodological improvements in the
CPI have taken place outside the revision framework. Among the
most prominent examples of these are the annual adjustment for
changes in the quality of new cars after model changeovers
introduced in 1967, the shift to flow-of-services measures of the
cost of owner-occupied housing in the early 1980s, and the
implementation of regression-based methods for quality adjustment
of apparel prices starting in 1991. Exhibit
1 presents a chronology of some of these changes. Also
outside the context of decennial revisions, the CPI program
develops experimental indexes of consumer prices corresponding to
population subgroups or using alternative aggregation formulas.
One example of such an experimental index is the CPI-E, an index
based on the expenditure patterns of consumer units with
reference persons aged 62 or older.3
Another index, currently under development, uses a geometric mean
formula to average the prices of items within CPI product
categories.4 Recently, the Bureau has
begun an evaluation effort to determine whether this geometric
mean formula should be adopted, in full or in part, in the
official CPI.
This current revision
occurs at a time of heightened public scrutiny of the CPI. As
mentioned above, CPI movements have a major influence on Federal
revenues and expenditures. Largely for this reason, issues
relating to the accuracy of the CPI have gained the attention of
observers both inside and outside of government.5
Most notably, following hearings in the spring of 1995, the
Senate Finance Committee appointed an advisory commission to
study the CPI and make recommendations for methodological
improvements.6
One source of
upward bias that has been of particular concern since its
discovery by BLS researchers was a technical problem that tied
the weight of a CPI sample item to its expected price change.
This flaw was effectively eliminated by the 1995 and 1996 changes
to CPI sample rotation and substitution procedures and to the
functional form used to calculate changes in the cost of shelter
for homeowners.7 Numerous issues
remain, however, all generally resulting from the dynamic nature
of U.S. consumer marketsnew goods, new types of outlets,
increases or decreases in product quality, and consumer
substitution behaviorand the difficulty of completely
reflecting such changes in the CPI. It is generally recognized
that the identification of solutions to most of these issues will
require much additional research. The 1998 revision, therefore,
is not designed to be a solution to, or even BLS response to,
issues of potential bias. Nevertheless, some components of the
revision are relevant to those issues.
Substitution bias,
for example, should be mitigated by the updating of CPI weights
and samples. The CPI, as a fixed-weighted index, generally
overstates changes in what economists call a true cost-of-living
index, because consumers can substitute toward categories of
goods and services whose relative prices have fallen. Elimination
of this bias would require the use of an alternative formula for
aggregating individual item indexes. The BLS produces
experimental U.S.-level indexes using such
"superlative" formulas,8
and research to enhance the accuracy of these indexes is
continuing. The data requirements of superlative formulas limit
the potential for their use in the official monthly CPI. It is
reasonable to expect, however, that the incorporation of more
up-to-date expenditure weights in 1998 will reduce the potential
gap between the official CPI and an index that fully reflects
current consumer spending patterns and responses. The updating of
the CPI geographic and housing samples should work in the same
direction.
The process of
incorporating new goods and new outlets into the CPI will be
enhanced by several aspects of the revision. First, the
redefinition of item categories is designed to facilitate the
introduction of wholly new types of goods and services that might
not have fit neatly into the existing CPI item structure. Second,
new item and outlet samples will be introduced in the geographic
areas that are new to the CPI, and in several item categories
that have been extensively redefined. The most important of the
latter categories is the hospital services component of the CPI,
where a new structuring of the index is specifically designed to
better reflect rapidly changing technology and treatment
patterns. Third, as part of the revision, the CPIs sample
rotation procedures are being redesigned to permit the
accelerated introduction of new items and outlets in those
product markets characterized by the most rapid change.
History. The
CPI was developed during World War I to meet the need of the
Federal Government in establishing cost-of-living adjustments for
workers in shipbuilding centers. Rapid increases in prices made
such an index essential for calculating these cost-of-living
adjustments. Regular publication of a national index began in
1921, based on the prices of 145 selected items in 32 industrial
cities and expenditure patterns corresponding to the 191719
period.9 Since that time, the Bureau
has updated, or revised, the CPI five times. Exhibit
2 shows the dates for each of the past revisions, and the
period of time during which expenditure patterns were collected
to provide the weights for the goods and services that comprise
the market basket. Consumer spending patterns during
198284, for example, have formed the basis for the CPI
weighting structure since January 1987. Effective with
publication of CPI data for January 1998, movements in the index
will be based on 199395 consumer expenditures.
Although reselecting
and reweighting the items in the CPI sample is fundamental to the
revision process, each historical revision has brought important
methodological innovations that improved the accuracy and
representativeness of the index. The 1940 revision, for example,
in addition to updating expenditure weights because peoples
buying patterns had changed substantially since the 191719
period, introduced the concept of a sample of cities and items as
well as the principle that the priced items could be used to
impute the price movement of similar non-priced items. Based on
this, the Bureau was able to publish price indexes for categories
of items, rather than for separate distinguished items.
During World War II,
when many commodities were scarce and goods were rationed, the
index weights were adjusted temporarily to reflect those
shortages. The first comprehensive postwar revision was completed
in January 1953, using weights from an expenditure survey
conducted in 1950. Both medium-sized and small cities were added
to the city sample to make the index representative of prices
paid by all urban wage earner and clerical worker families.10
After the 1953
revision, it became apparent that the CPI needed to be revised
every decade.11 As a result, the
next revision was completed in 1964. For the first time, the
expenditure weights included single persons as well as families.
In addition, computer processing was used for the first time in
the 1964 revision.12
The 1978 CPI
revision implemented a variety of fundamental changes, many of
which were stimulated by the 1961 report of the Price Statistics
Review Committee headed by future Nobel Prize winner George J.
Stigler.13 The revision introduced a
quarterly survey approach to the collection of consumer
expenditures as well as numerous improvements and innovations in
pricing for the CPI. Additionally, 1978 saw the introduction of a
second index of consumer prices, a more broadly-based CPI for All
Urban Consumers, or CPI-U. This index differed from the CPI for
Urban Wage Earners and Clerical Workers (CPI-W) by including the
buying patterns of all urban households regardless of the
consumer units occupational status.
The sampling process
of the CPI also moved to a more comprehensive and sophisticated
statistical basis in 1978. A new store-specific approach to the
item selection process, called disaggregation, was introduced.
Perhaps the most significant innovation in the 1978 revision was
the introduction of the Point-of-Purchase Survey (POPS). In the
POPS, consumer units were interviewed in each geographic area
covered in the CPI. Respondents identified the actual stores and
other retail outlets in which they shopped and specified the
amount they spent for a category of items.
The most recent
revision was completed in 1987 and updated the CPI to
198284 expenditure patterns. Unlike previous revisions in
which all new areas and items were replaced at the same time, the
1987 revision introduced the concept of "rolling-in."
New areas, items, and outlet samples were gradually introduced
over a period of years using existing updating procedures.14 The use of systematic sample
rotation was also broadened.15
Finally, the 1987 revision introduced the use of an advanced
model for CPI sample allocation. The model uses nonlinear
programming techniques to determine the distributions of item and
outlet selections across all item and geographic strata and to
minimize overall price change sampling variance subject to
certain budgetary and operational constraints.
The 1998 revision
The most basic aspect of this revision will be the
incorporation of a new set of expenditure weights. Consumer
Expenditure Survey data from 199395 will be used to
calculate a new expenditure weight for each item strata category
in every CPI index area. These new market basketsnew
geographic area samples, new item structure, and new expenditure
weightswill take effect with the index for January 1998. At
the same time, many of the samples underlying the CPI will be
replaced. These samples include geographic areas, items selected
for pricing, and outlets in which items are priced.
Geographic sample. The geographic sample
selection process uses stratified sampling to represent the U.S.
urban population. Eighty-seven geographic areas, known as primary
sampling units, were selected for the revised CPI based on the
1990 decennial census. These units replace the current primary
sampling units, which are representative of the 1980 U.S.
population distribution. Thirty primary sampling units where
prices are currently collected, including Anchorage and Honolulu,
were selected with certainty. Another 21 units in the current
design were also selected again. Thirty-six new primary sampling
units were selected to replace units in the current CPI
geographic sample. These 36 new areas will have new outlet and
item pricing samples introduced into the revised index for
January 1998. As part of the reselection process, the present
three metropolitan-area size categories will be consolidated into
two. Details on the redesigned CPI geographic sample and the
procedures used to select that sample are in "The redesign of the CPI geographic
sample."
Item structure. As the geographic sample
must reflect todays population, the CPI market basket needs
to be updated to represent current consumption patterns. The item
strata (the groupings of items into homogeneous categories for
publication) will be redefined and the way in which they are
aggregated will change based on shifts taking place in the
marketplace. For example, the present seven major groups of goods
and services will be restructured into eight major groups with
the creation of the education and communication
group. That new group includes components previously included in
the housing and other goods and
servicesgroups. The new item structure, along with a
summary of the assumptions underlying the development of the new
structure, are in "Changing the item
structure of the Consumer Price Index."
The selection of
commodities and services samples during the revision will benefit
from the results of an expanded and re-estimated CPI sample
optimization model. As compared with the models used in earlier
years, the new design will lead to the selection of relatively
fewer outlets and more items per outlet. Also, there will be a
broad shift in relative sample size away from the food and
beverages category and toward the other major groups. These
changes occur largely because updated and improved variance
estimates were used in the estimation of the optimization model,
and additional sample share constraints were imposed.16
Publication strategy. The selection of new
geographic areas and modernization of the item structure will
necessarily result in changes in the number and mix of published
CPI series. In addition, during the revision, the publication
criteria and procedures have been reviewed extensively. BLS will
develop a variance-based publication strategy in which the level
of detail published is based on the variance surrounding its item
index estimates.
As in the past, the
Bureau will publish overlap indexes based on both the new and the
old item structure and expenditure weight for several months
beginning in February 1998. These overlap indexes will permit
users to see first-hand the revisions effect on the
published rate of inflation. Also, effective with the index for
January 1999, the CPI will change from a 198284 = 100 to a
199395 = 100 reference base. Details on the new CPI
publication system and structure are in "Publication
strategy for the 1998 revised Consumer Price Index."
Housing. The housing portion of the CPI
revision has two fundamental components, both of which will be
implemented with the index for January 1999: the shift
to an improved estimation method for homeowner shelter costs, and
the selection of a new housing unit sample using the 1990
decennial census. The new estimator for owners equivalent
rent will be based on the reweighting of the same rental
observations that are used for the residential rent index. In the
current CPI estimator, implicit rents for a sample of
owner-occupied units are estimated by matching those units to
specific rental units. The new method will not require selection
of an owner-occupied sample.
This new sample will
provide a current set of rental housing units that, as noted
above, will be priced to calculate indexes for both residential
rent and owners equivalent rent. The decennial census
provides information that will be used to select the
housing segments within geographic areas. This
selection process utilizes stratification criteria to locate
segments that represent the housing stock throughout the
geographic area, and also determines the sampling rates that will
be used to derive the appropriate total sample of housing units.
Housing units will be selected to support the initial revised
sample, as well as the shadow samples that will be rotated into
the CPI in later years to reduce respondent burden and refresh
the sample. In addition, new housing units constructed since the
decennial census will be brought into the CPI housing sample
through an augmentation process. Additional information on the
changes to the housing component of the CPI is in "Revision of the CPI housing sample and
estimators."
Hospital services. The medical care
component of the CPI also will be extensively revised to reflect
the dramatic changes taking place in this sector of the economy,
particularly in the delivery of hospital services. Effective with
the index for January 1997, the three item strata within the
hospital and related services category will be consolidated into
two, with only a single hospital services stratum. Pricing
procedures are also being fundamentally revised, from pricing
individual items (such as a unit of blood or a hospital inpatient
day) to pricing the combined sets of goods and services provided
on selected patient bills. These changes support the collection
of transaction prices and facilitate the measurement of price
change in an area where the products and services available are
undergoing significant change. A full description of these
revisions is in "Revision of the CPI
hospital services component."
Other enhancements. Several technological
enhancements are planned for the CPI revision as well. We will
modernize the processing systems for both the Consumer
Expenditure Survey and the housing sample of rental prices. Each
of these complex computer processing systems has reached the end
of its current life-cycle, and will be modernized to stay current
with technology. This revision will also build on the
Point-of-Purchase Survey and significantly improve it by
utilizing computer-assisted telephone data collection.
Utilization of a shorter interview and edits at the point of
collection should lead to faster data turnaround and consequently
more up-to-date information on the distribution of consumer
spending across outlets. Based on the improved survey
methodology, BLS can introduce new outlets and items into the CPI
more rapidly and efficiently. Moreover, the new Point-of-Purchase
Survey sample design will permit a shift to sample rotation by
category rather than by geographic area, and thereby facilitate
accelerated sample rotation in product areas where markets are
most dynamic. The article, "New
methodology for selecting CPI outlet samples," describes
this new methodology and its implementation.
A final, crucial
element in the current revision is the conversion to electronic
systems of all commodities-and-services and housing data
collection and transmission. A fully-implemented
computer-assisted data collection (CADC) system for the CPI will
significantly improve the overall quality of CPI data. While
quality improvement is the primary justification for CADC,
electronic data collection and transmission will probably provide
long-term savings through a reduction of mail, paper and printing
costs, and a transfer of some edit and review functions from the
BLS national office to the local data collector.
CADC instruments will
help to assure consistent application of survey rules and data
review decisions at the point of collection. The results will be
increased accuracy of collected data, greater conformance with
collection procedures, a higher percentage of successfully
completed collection schedules, and an increase in the yield of
usable quotes per release of the index. Electronic data
transmission also will allow collection of prices closer to the
end of the month, improving coverage of price changes during the
reference period.
The initial CADC
system implementation, Version I, will be a fully reliable system
that meets current data collection standards and will be a
foundation upon which future enhancements can be built with
confidence. This version will include all functionality necessary
for housing. There will be basic edits and checks for collected
data. In addition, a survey information and control system will
be developed that will provide up-to-date information on the
status and location of all housing data collection activities.
Implementation of Version I will begin in 1997 and will be
completed in 1998.
Strategically, we
will build on our computer data collection experience with the
housing data before undertaking the pricing and initiation of
commodities and services in retail establishments. In Version II,
there will be more functionality for initiation, and edits and
checks will be expanded. The survey information and control
system will likewise expand to control the larger volume of data
collected for commodities and services. After Version II is
operating smoothly, a part of the commodity analyst review will
be incorporated into the CADC system at the point of collection.
This will provide automatic checks for the comparability of item
substitutions and transfer more functions from the national
office staff to the regional staff.
THE MOST SIGNIFICANT MILESTONES in the overall revision
schedule are presented in exhibit 3. The
conclusion of the revision in 2000 does not mean the end of the
CPI improvement process. BLS will continue to enhance its program
of experimental indexes and research on CPI measurement issues.
It is also reasonable to expect that the recommendations of the
Senate Finance Committees Advisory Commission, as well as
the results of other studies of the CPI by outside researchers,
will lead to additions in the list of CPI improvements outside
the revision context. Nevertheless, the decennial revision
process remains the central method by which the BLS maintains the
quality of the CPI and thereby ensures the indexs status as
the most accurate and timely measure of changes in consumer
prices.
|
Exhibit
1. Improvements to the Consumer
Price Index
|
| Change
|
Date
implemented
|
Description |
| New construction |
1966
|
Rent samples augmented with
units built after 1960. |
| Quality adjustment of new
automobile prices |
1967
|
New automobile prices
adjusted for quality differences after model changeovers. |
| Sample rotation |
1981
|
Introduced a systematic
replacement of outlets between major revisions. |
| Rental equivalence |
1983
|
Changed homeowners'
component from cost of purchase to value of rental
services for CPI-U. |
| Return from sale price
imputation |
1984
|
Introduced procedure to
eliminate downward bias for items discontinued by outlets
that went out of index with discounted prices. |
| Rental equivalence |
1985
|
Changed CPI-W homeowners'
component to value of services. |
| Enhanced seasonal products
methodology |
1987
|
Enhanced methodology used
for seasonal items by expanding the number of price
quotations to select products from alternate seasons and
eliminate under-representation of such items. |
| Quality adjustment of used
car prices |
1987
|
Prices of used cars adjusted
for differences in quality after model changeovers. |
| Aging bias correction |
1988
|
Rental values adjusted for
aging of the housing stock. |
| Imputation procedures for
new cars and trucks |
1989
|
Price changes for
noncomparable new models are imputed using only the
constant-quality price changes for comparable model
changeovers. |
| Quality adjustment of
apparel prices |
1991
|
Regression models used to
adjust apparel prices for changes in quality when new
clothing lines are introduced, and eliminate bias due to
linking product substitutions into the CPI. |
| Discount air fares |
1991
|
Substitution rules modified
to expand pricing of discount airline fares. |
| Sample augmentation |
1992
|
Increase in the number of
outlets from which prices are collected to replace sample
lost through sample attrition. |
| New models imputation |
1992
|
Refined imputation methods
used when introducing products into the CPI. |
| Hotels & motels |
1992
|
Samples for hotels and
motels quadrupled to reduce variances related to seasonal
pricing. |
| Seasonal adjustment |
1994
|
Procedures for seasonal
adjustment revised to eliminate residual seasonality
effects. |
| Quality adjustment for
gasoline |
1994
|
Treat
"reformulated" gasoline as a quality change and
adjust the price to reflect quality difference. Impact of
the change estimated. |
| Generic drugs |
1995
|
Introduced new procedures
that allow generic drugs to be priced when a brand drug
loses its patent. |
| Food at home base period
prices |
1995
|
Introduced seasoning
procedures to eliminate upward bias in setting of base
period prices of newly initiated items. |
| Rental equivalence |
1995
|
Modified imputation of
homeowners' implicit rent to eliminate the upward drift
property of the current estimator. |
| Composite estimator used in
housing |
1995
|
Replaced current composite
estimator with a 6-month chain estimator. Under-reporting
of 1-month rent changes had resulted in missing price
change in residential rent and homeowners' equivalent
rent. Old estimator also produced higher variances. |
| Commodities and services
base period prices |
1996
|
Extended food-at-home
seasoning procedures to remainder of commodities and
services series. Base period prices left unchanged in
most noncomparable substitutions. |
|
Exhibit 2.
Previous CPI revisions
|
| Release of revised
CPI |
Expenditure base
period |
Notable
innovations |
| 1940 |
1934-36 |
Introduced the concept of a sample of
cities and items, and the principle of imputation |
| 1953 |
1950 |
Expanded population coverage to represent
all urban wage earner and clerical worker families |
| 1964 |
1960-61 |
Expanded population coverage to represent
individuals as well as families; introduced computer
processing |
| 1978 |
1972-73 |
Expanded population coverage to represent
all urban consumers; improved methodology for
construction of outlet sample frame; introduced
probability sampling techniques into the selection of the
item and outlet samples |
| 1987 |
1982-84 |
Expanded scope of systematic outlet
rotation; introduced advanced sample allocation model |
|
Exhibit 3.
Major milestones in the 1998 CPI revision
|
| Milestone |
Date |
| Introduce revised hospital services item
structure and sample |
February 1997 (index for January 1997) |
| Introduce new geographic sample and item
structure and update expenditure weights to 1993-95 |
February 1998 (index for January 1998) |
| Begin pricing of new housing sample using
computer-assisted data collection |
June 1998 |
| Introduce new housing sample and
estimator into CPI |
February 1999 (index for January 1999) |
| Rebase CPI to 199395 =100 |
February 1999 (index for January 1999) |
| Introduce computer-assisted data
collection for commodities and services sample |
Summer 1999 |
| Begin shift from area sample rotation to
item category rotation using telephone Point-of-Purchase
Survey |
Early 1999 |
| Enter redesigned Consumer Expenditure
Survey processing system into full production |
October 1999 |
Acknowledgment:
The authors are grateful to Marybeth Tschetter for her
comments, suggestions and assistance during the preparation of
this paper and the others in this volume. Sylvia Leaver, Frank
Ptacek, and Janet Williams also provided helpful comments on the
paper. Finally, the authors would like to acknowledge the
contributions of John Marcoot, who played a fundamental role in
the design and execution of the 1998 CPI Revision as well as
earlier revisions.
Footnotes
1 Office of
Management and Budget estimate, as reported in BLS budget
documents.
2 Handbook of
Methods, Bulletin 2285 (Bureau of Labor Statistics, 1988)
"Chapter 19. The Consumer Price Index."
3 For a
description of the construction of, and recent movements in, the
CPI-E, see Kenneth Stewart and Joseph Pavalone,
"Experimental CPI for Americans 62 years of age and
older," CPI Detailed Report, April 1996.
4 Theoretical and
empirical comparisons of the geometric mean formula to the
arithmetic mean formula used in the CPI are presented in Brent
Moulton and Karin Smedley, "A Comparison of Estimators for
Elementary Aggregates of the CPI," Bureau of Labor
Statistics Working Paper, June 1995.
5 For general
reviews of these issues see, for example, Dennis Fixler,
"The Consumer Price Index: underlying concepts and
caveats," Monthly Labor Review, December 1993, pp.
312; Is the Growth of the CPI a Biased Measure of
Changes in the Cost of Living? (Congressional Budget Office,
October 1994); Report for the House Budget Committee (Bureau of
Labor Statistics, 1995); Matthew Shapiro and David Wilcox,
"Mismeasurement in the Consumer Price Index: An
Evaluation," NBER Macroeconomics Annual 1996
(Cambridge, MA, National Bureau of Economic Research,
forthcoming); and Brent R. Moulton, "Bias in the Consumer
Price Index: What is the Evidence?" Journal of Economic
Perspectives, Fall 1996, pp. 15977.
6 See Consumer
Price Index, Hearings before the Committee on Finance, U.S.
Senate, U.S. Government Printing Office, 1995; and Toward a
More Accurate Measure of the Cost of Living, Final Report to
the Senate Finance Committee from the Advisory Commission to
Study the Consumer Price Index, December 4, 1996.
7 For details on
these changes, see Steve Henderson and Karin Smedley,
"Improvements in estimating the shelter indexes in the
CPI," CPI Detailed Report, October 1994, pp.
56; Ken Stewart, "Improving CPI sample rotation
procedures," CPI Detailed Report, October 1994, pp.
78; Ken Stewart, "Extending the improvement in CPI
sample rotation procedures," CPI Detailed Report,
June 1996, pp. 910; and Kenneth J. Stewart, "Improving
CPI item substitution procedures," CPI Detailed Report,
July 1996, pp. 89.
8 See, for
example, Ana Aizcorbe and Patrick Jackman, "The commodity
substitution effect in CPI data, 198291," Monthly
Labor Review, December 1993, pp. 2533.
9 The Consumer
Price Index: History and Techniques, Bulletin 1517
(Bureau of Labor Statistics), p. 2; and The First Hundred
Years of the Bureau of Labor Statistics (Bureau of Labor
Statistics, September 1985) pp. 9497.
10 Handbook of
Methods, Bulletin 2285 (Bureau of Labor Statistics, 1992), p.
154.
11 Sidney Jaffe,
"The Consumer Price IndexTechnical Questions and
Practical Answers," Paper presented to the American
Statistical Association, Dec. 30, 1959.
12 John Marcoot,
"Revision of Consumer Price Index is now underway," Monthly
Labor Review, April 1985, p. 28.
13 Government
Price Statistics, U.S. Congress, Joint Economic Committee,
87th Cong., 1st Sess., January 24, 1961.
14 The rolling-in
approach effected significant cost and time savings. Rolling-in
the new areas into the CPI allowed more time to train field
representatives. More importantly, using the existing procedures
for introducing new outlet samples on a systematic basis
precluded the need to maintain dual operations, one for the
current CPI and one for the revised index.
15 Marcoot,
"Revision of Consumer Price Index."
16 S.G. Leaver,
W. H. Johnson, R.M. Baskin, S. Scarlett, and R. Morse,
"Commodities and Services Sample Redesign for the 1998
Consumer Price Index Revision," Proceedings of the Survey
Research Methods Section, American Statistical Association,
forthcoming.
John S. Greenlees is Assistant Commissioner for Consumer
Prices and Price Indexes and Charles C. Mason is an economist in
the Division of Consumer Prices and Price Indexes, Bureau of
Labor Statistics.
Last Modified Date: October 16, 2001