Transmission of material in this release is embargoed until
8:30 a.m. (EDT) October 18, 2016 USDL-16-2023
Technical information: (202) 691-7000 Reed.Steve@bls.gov www.bls.gov/cpi
Media Contact: (202) 691-5902 PressOffice@bls.gov
CONSUMER PRICE INDEX – SEPTEMBER 2016
The Consumer Price Index for All Urban Consumers (CPI-U) increased 0.3 percent
in September on a seasonally adjusted basis, the U.S. Bureau of Labor Statistics
reported today. Over the last 12 months, the all items index rose 1.5 percent
before seasonal adjustment.
Increases in the shelter and gasoline indexes were the main causes of the rise
in the all items index. The gasoline index rose 5.8 percent in September and
accounted for more than half of the all items increase. The shelter index
increased 0.4 percent, its largest increase since May.
The energy index increased 2.9 percent, its largest advance since April. Along
with the gasoline index, other energy component indexes also rose. The index for
food, in contrast, was unchanged for the third consecutive month, as the food at
home index continued to decline.
The index for all items less food and energy rose 0.1 percent in September after
a 0.3-percent increase in August. Along with the shelter index, the indexes for
medical care, motor vehicle insurance, and personal care all increased in
September, as did the indexes for education, alcoholic beverages, airline fares,
and tobacco. The indexes for communication, apparel, used cars and trucks,
recreation, and new vehicles all declined.
The all items index rose 1.5 percent for the 12 months ending September, its
largest 12-month increase since October 2014. The index for all items less food
and energy rose 2.2 percent for the 12 months ending September. The food index
declined 0.3 percent over the span, and the energy index fell 2.9 percent.
-------------------------------------------------------------------------------------
Corrections to Prescription Drug Indexes
The indexes for prescription drugs were incorrect as published for May 2016 through
August 2016, which affected the U.S. All items index. Incorrect prices were used in
the calculation of indexes in several local areas. A list of the series affected by
the errors can be found at www.bls.gov/bls/errata/cpi-price-corrections-10182016.htm.
-------------------------------------------------------------------------------------
Table A. Percent changes in CPI for All Urban Consumers (CPI-U): U.S. city
average
Seasonally adjusted changes from
preceding month
Un-
adjusted
12-mos.
Mar. Apr. May June July Aug. Sep. ended
2016 2016 2016 2016 2016 2016 2016 Sep.
2016
All items.................. .1 .4 .2 .2 .0 .2 .3 1.5
Food...................... -.2 .2 -.2 -.1 .0 .0 .0 -.3
Food at home............. -.5 .1 -.5 -.3 -.2 -.2 -.1 -2.2
Food away from home (1).. .2 .2 .2 .2 .2 .2 .2 2.4
Energy.................... .9 3.4 1.2 1.3 -1.6 .0 2.9 -2.9
Energy commodities....... 1.9 7.8 2.4 3.3 -4.4 -.9 5.5 -6.4
Gasoline (all types).... 2.2 8.1 2.3 3.3 -4.7 -.9 5.8 -6.5
Fuel oil (1)............ 1.7 1.9 6.2 3.3 -1.3 -2.5 2.4 -8.5
Energy services.......... .2 -.1 .2 -.5 1.0 .8 .7 .7
Electricity............. .4 -.3 -.2 -.5 .5 .5 .7 .1
Utility (piped) gas
service.............. -.7 .6 1.7 -.4 3.1 2.1 .8 2.9
All items less food and
energy................. .1 .2 .2 .2 .1 .3 .1 2.2
Commodities less food and
energy commodities.... -.2 -.1 -.2 -.3 -.1 .1 -.1 -.6
New vehicles............ .0 -.3 -.1 -.2 .2 .0 -.1 .0
Used cars and trucks.... -.1 -.3 -1.3 -1.1 -1.0 -.6 -.3 -4.1
Apparel................. -1.1 -.3 .8 -.4 .0 .2 -.7 -.1
Medical care commodities .3 .5 -.4 .8 .5 1.4 .6 5.2
Services less energy
services.............. .2 .3 .3 .3 .2 .3 .2 3.2
Shelter................. .2 .3 .4 .3 .2 .3 .4 3.4
Transportation services .2 .7 .3 .3 -.2 .1 .0 3.0
Medical care services... .1 .3 .5 .2 .5 1.0 .0 4.8
1 Not seasonally adjusted.
Food
The food index was unchanged in September, as it was in July and August. The index
for food away from home increased 0.2 percent, but the food at home index declined
for the fifth consecutive month, falling 0.1 percent. Major grocery store food group
indexes were mixed, with three declines and three increases. The index for
nonalcoholic beverages fell 0.4 percent in September, its fourth decline in the last
5 months. The fruits and vegetables index, which was unchanged in August, fell
0.3 percent in September. The index for meats, poultry, fish, and eggs continued to
fall, declining 0.2 percent, with the beef index falling 0.5 percent.
In contrast, the indexes for cereals and bakery products, dairy and related products,
and other food at home all rose slightly in September, each increasing 0.1 percent.
Over the last 12 months, the food at home index has declined 2.2 percent, the largest
12-month decline since December 2009. All six major grocery store food group indexes
declined over the last year. The index for food away from home has risen 2.4 percent
since September 2015.
Energy
The energy index rose in September, increasing 2.9 percent after being unchanged in
August. All major energy component indexes increased. The gasoline index, which fell
0.9 percent in August, rose 5.8 percent in September. (Before seasonal adjustment,
gasoline prices increased 2.3 percent in September.) The fuel oil index also
increased in September, rising 2.4 percent. The electricity index increased
0.7 percent in September, its third straight increase and largest since December
2014. The index for natural gas also continued to rise, increasing 0.8 percent in
September following larger increases in July and August.
The energy index has declined 2.9 percent over the past year; this is the smallest
12-month decline since the period ending October 2014. The gasoline index has
declined 6.5 percent over the last year, and the index for fuel oil has decreased
8.5 percent. However, the index for natural gas has risen 2.9 percent over the past
year, and the electricity index has advanced slightly, increasing 0.1 percent.
All items less food and energy
The index for all items less food and energy increased 0.1 percent in September after
rising 0.3 percent in August. The shelter index increased 0.4 percent in September,
reflecting a 0.3-percent increase in the rent index and a 0.4-percent advance in the
index for owners' equivalent rent. The index for medical care rose, though the
0.2 percent increase in September was the smallest increase since March. The index for
prescription drugs increased 0.8 percent, while the hospital services index was
unchanged. The index for motor vehicle insurance continued to rise, increasing
0.4 percent in September. The personal care index increased in September, advancing
0.4 percent. The index for airline fares rose 0.4 percent, following declines in July
and August. The index for tobacco also increased 0.4 percent, while the alcoholic
beverages index rose 0.3 percent and the education index advanced 0.2 percent.
In contrast to these increases, several indexes declined in September. The index for
communication fell 0.8 percent, its largest decline since October 2014, and the apparel
index decreased 0.7 percent. The index for used cars and trucks continued to fall,
declining 0.3 percent in September. The indexes for new vehicles and for recreation both
fell 0.1 percent, while the index for household furnishings and operations was unchanged.
The index for all items less food and energy increased 2.2 percent over the past 12 months.
The 12- month increase has stayed in the narrow range of 2.1 percent to 2.3 percent since
December 2015. The shelter index has risen 3.4 percent over the last 12 months, and the
medical care index has increased 4.9 percent.
Not seasonally adjusted CPI measures
The Consumer Price Index for All Urban Consumers (CPI-U) increased 1.5 percent over the
last 12 months to an index level of 241.428 (1982-84=100). For the month, the index
increased 0.2 percent prior to seasonal adjustment.
The Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W) increased
1.2 percent over the last 12 months to an index level of 235.495 (1982-84=100). For the
month, the index increased 0.3 percent prior to seasonal adjustment.
The Chained Consumer Price Index for All Urban Consumers (C-CPI-U) increased 1.2 percent
over the last 12 months. For the month, the index rose 0.3 percent on a not seasonally
adjusted basis. Please note that the indexes for the past 10 to 12 months are subject
to revision.
The Consumer Price Index for October 2016 is scheduled to be released on Thursday,
November 17, 2016, at 8:30 a.m. (EST).
----------------------------------------------------------------------------------------
Consumer Price Index Geographic Revision for 2018
In January 2018, BLS will introduce a new geographic area sample for the Consumer Price
Index (CPI). The 2018 revision utilizes the 2010 Decennial Census and incorporates an
updated area sample design, changes the frequency of publication for several local area
indexes, and establishes some new local area and aggregate indexes. The first indexes
using the new structure will be published in February 2018. Additional information on
the geographic revision is available at: www.bls.gov/cpi/georevision2018.htm.
-----------------------------------------------------------------------------------------
Facilities for Sensory Impaired
Information from this release will be made available to sensory impaired individuals
upon request. Voice phone: 202-691-5200, Federal Relay Services: 1-800-877-8339.
Brief Explanation of the CPI
The Consumer Price Index (CPI) is a measure of the average change in prices over
time of goods and services purchased by households. The Bureau of Labor Statistics
publishes CPIs for two population groups: (1) the CPI for Urban Wage Earners and
Clerical Workers (CPI-W), which covers households of wage earners and clerical workers
that comprise approximately 28 percent of the total population and (2) the CPI for All
Urban Consumers (CPI-U) and the Chained CPI for All Urban Consumers (C-CPI-U), which
covers approximately 89 percent of the total population and includes, in addition to
wage earners and clerical worker households, groups such as professional, managerial,
and technical workers, the self-employed, short-term workers, the unemployed, and
retirees and others not in the labor force.
The CPIs are based on prices of food, clothing, shelter, fuels, transportation fares,
charges for doctors’ and dentists’ services, drugs, and other goods and services that
people buy for day-to-day living. Prices are collected each month in 87 urban areas
across the country from about 6,000 housing units and approximately 24,000 retail
establishments-department stores, supermarkets, hospitals, filling stations, and other
types of stores and service establishments. All taxes directly associated with the
purchase and use of items are included in the index. Prices of fuels and a few other
items are obtained every month in all 87 locations. Prices of most other commodities
and services are collected every month in the three largest geographic areas and every
other month in other areas. Prices of most goods and services are obtained by personal
visits or telephone calls of the Bureau’s trained representatives.
In calculating the index, price changes for the various items in each location are
averaged together with weights, which represent their importance in the spending of the
appropriate population group. Local data are then combined to obtain a U.S. city average.
For the CPI-U and CPI-W separate indexes are also published by size of city, by region of
the country, for cross-classifications of regions and population-size classes, and for 27
local areas. Area indexes do not measure differences in the level of prices among cities;
they only measure the average change in prices for each area since the base period. For
the C-CPI-U data are issued only at the national level. It is important to note that the
CPI-U and CPI-W are considered final when released, but the C-CPI-U is issued in
preliminary form and subject to two annual revisions.
The index measures price change from a designed reference date. For the CPI-U and the
CPI-W the reference base is 1982-84 equals 100. The reference base for the C-CPI-U is
December 1999 equals 100. An increase of 16.5 percent from the reference base, for
example, is shown as 116.500. This change can also be expressed in dollars as follows:
the price of a base period market basket of goods and services in the CPI has risen
from $10 in 1982-84 to $11.65.
For further details visit the CPI home page on the Internet at www.bls.gov/cpi/ or
contact our CPI Information and Analysis Section on (202) 691-7000.
Note on Sampling Error in the Consumer Price Index
The CPI is a statistical estimate that is subject to sampling error because it is based
upon a sample of retail prices and not the complete universe of all prices. BLS
calculates and publishes estimates of the 1-month, 2-month, 6-month and 12-month percent
change standard errors annually, for the CPI-U. These standard error estimates can be
used to construct confidence intervals for hypothesis testing. For example, the estimated
standard error of the 1 month percent change is 0.04 percent for the U.S. All Items
Consumer Price Index. This means that if we repeatedly sample from the universe of all
retail prices using the same methodology, and estimate a percentage change for each sample,
then 95% of these estimates would be within 0.08 percent of the 1 month percentage change
based on all retail prices. For example, for a 1-month change of 0.2 percent in the All
Items CPI for All Urban Consumers, we are 95 percent confident that the actual percent
change based on all retail prices would fall between 0.12 and 0.28 percent. For the latest
data, including information on how to use the estimates of standard error, see "Variance
Estimates for Price Changes in the Consumer Price Index, January-December 2014." These
data are available on the CPI home page (www.bls.gov/cpi), or by using the following
link: www.bls.gov/cpi/cpivar2014.pdf.
Calculating Index Changes
Movements of the indexes from one month to another are usually expressed as percent changes
rather than changes in index points, because index point changes are affected by the level
of the index in relation to its base period while percent changes are not. The example
below illustrates the computation of index point and percent changes.
Percent changes for 3-month and 6-month periods are expressed as annual rates and are
computed according to the standard formula for compound growth rates. These data indicate
what the percent change would be if the current rate were maintained for a 12-month period.
Index Point Change
CPI 202.416
Less previous index 201.800
Equals index point change .616
Percent Change
Index point difference .616
Divided by the previous index 201.800
Equals 0.003
Results multiplied by one hundred 0.003x100
Equals percent change 0.3
A Note on the Use of Seasonally Adjusted and Unadjusted Data
Introduction
The Consumer Price Index (CPI) produces both unadjusted and seasonally adjusted data.
Seasonally adjusted data are computed using seasonal factors derived by the X-13ARIMA-SEATS
Seasonal Adjustment Method. These factors are updated each February, and the new factors are
used to revise the previous five years of seasonally adjusted data. For more information on
data revisions and exceptions to the usual revision schedule, please see the Fact Sheet on
Seasonal Adjustment (http://www.bls.gov/cpi/cpisaqanda.htm) and the Timeline of Seasonal
Adjustment Methodological Changes (http://www.bls.gov/cpi/cpiseastimeline.htm).
How to Use Seasonally Adjusted and Unadjusted Data
For analyzing short-term price trends in the economy, seasonally adjusted changes are usually
preferred since they eliminate the effect of changes that normally occur at the same time and
in about the same magnitude every year—such as price movements resulting from changing
climatic conditions, production cycles, model changeovers, holidays, and sales. This allows
data users to focus on changes that are not typical for the time of year. The unadjusted data
are of primary interest to consumers concerned about the prices they actually pay. Unadjusted
data are also used extensively for escalation purposes. Many collective bargaining contract
agreements and pension plans, for example, tie compensation changes to the Consumer Price Index
before adjustment for seasonal variation. BLS advises against the use of seasonally adjusted
data in escalation agreements because seasonally adjusted series are revised annually.
Intervention Analysis
The Bureau of Labor Statistics uses Intervention Analysis Seasonal Adjustment for some CPI
series. Sometimes extreme values or sharp movements can distort the underlying seasonal pattern
of price change. Intervention Analysis Seasonal Adjustment is a process by which the distortions
caused by such unusual events are estimated and removed from the data prior to calculation of
seasonal factors. The resulting seasonal factors, which more accurately represent the seasonal
pattern, are then applied to the unadjusted data.
2016 Series Adjusted Using Intervention Analysis Seasonal Adjustment
For the seasonal factors introduced in January 2016, BLS adjusted 37 series using Intervention
Analysis Seasonal Adjustment, including selected food and beverage items, motor fuels and natural
gas. For example, this procedure was used for the Motor fuel series to offset the effects of
events such as the response in crude oil markets to the worldwide economic downturn in 2008.
Revision of Seasonally Adjusted Indexes
Seasonally adjusted data, including the U.S. city average All items index levels, are subject to
revision for up to five years after their original release. Every year, economists in the CPI
calculate new seasonal factors for seasonally adjusted series and apply them to the last five years
of data. Seasonally adjusted indexes beyond the last five years of data are considered to be final
and not subject to revision. In January 2016, revised seasonal factors and seasonally adjusted
indexes for 2011-2015 were calculated and published. For directly adjusted series, the seasonal
factors for 2015 will be applied to data in 2016 to produce the seasonally adjusted 2016 indexes.
Determining Seasonal Status
Each year the seasonal status of every series is reevaluated based upon certain statistical criteria.
Using these criteria, BLS economists determine whether a series should change its status: from "not
seasonally adjusted" to "seasonally adjusted", or vice versa. If any of the 81 components of the U.S.
city average all items index change their seasonal adjustment status from seasonally adjusted to not
seasonally adjusted, not seasonally adjusted data will be used in the aggregation of the dependent
series for the last five years, but the seasonally adjusted indexes before that period will not be
changed. 28 of the 81 components of the U.S. city average all items index are not seasonally adjusted
for 2016.
Contact Information
For additional information on seasonal adjustment in the CPI, please write to the Bureau of Labor
Statistics, Division of Consumer Prices and Price Indexes, Washington, DC 20212 or contact Justin
Yarros, Samuel An or Marie Rogers at (202) 691-6968 or by e-mail at Yarros.Justin@bls.gov,
An.Samuel@bls.gov or Rogers.Marie@bls.gov. If you have general questions about the CPI, please call
our information staff at (202) 691-7000.
