Consumer Price Index Summary

 Transmission of material in this release is embargoed until                                        
 8:30 a.m. (EDT) Wednesday, September 16, 2015  USDL-15-1786

 Technical information: (202) 691-7000
 Media Contact:         (202) 691-5902 


 The Consumer Price Index for All Urban Consumers (CPI-U) decreased 0.1 
 percent in August on a seasonally adjusted basis, the U.S. Bureau of Labor
 Statistics reported today. Over the last 12 months, the all items index 
 rose 0.2 percent before seasonal adjustment.

 The gasoline index declined sharply in August and was the main cause of 
 the seasonally adjusted all items decrease. Other energy indexes were 
 mixed, with the fuel oil index continuing to decline but the indexes for 
 electricity and natural gas increasing in August. The food index rose 0.2
 percent in August, with the indexes for eggs and for fruits and vegetables
 rising notably.

 The index for all items less food and energy increased 0.1 percent in
 August, the same increase as in July. The index for shelter rose, as did
 the indexes for apparel, tobacco, and alcoholic beverages. However the
 index for airline fares declined sharply, and the indexes for household
 furnishings and operations, recreation, and used cars and trucks also
 decreased in August, with the indexes for new vehicles and medical care

 The all items index increased 0.2 percent for the 12 months ending August,
 the same increase as for the 12 months ending July. The 12-month change
 in the index for all items less food and energy also remained the same,
 at 1.8 percent for the 12 months ending August. The food index rose 1.6
 percent over the last 12 months, while the energy index declined 15.0

 Table A. Percent changes in CPI for All Urban Consumers (CPI-U): U.S. city
                                  Seasonally adjusted changes from             
                                          preceding month                      
                              Feb.  Mar.  Apr.  May   June  July  Aug.   ended 
                              2015  2015  2015  2015  2015  2015  2015   Aug.  
 All items..................    .2    .2    .1    .4    .3    .1   -.1       .2
  Food......................    .2   -.2    .0    .0    .3    .2    .2      1.6
   Food at home.............    .1   -.5   -.2   -.2    .4    .3    .3       .8
   Food away from home (1)..    .3    .2    .2    .2    .2    .0    .2      2.7
  Energy....................   1.0   1.1  -1.3   4.3   1.7    .1  -2.0    -15.0
   Energy commodities.......   2.1   3.8  -1.9   9.6   3.1    .7  -4.1    -23.6
    Gasoline (all types)....   2.4   3.9  -1.7  10.4   3.4    .9  -4.1    -23.3
    Fuel oil (1)............   1.9   5.9  -8.4    .7  -1.9  -3.4  -8.1    -34.6
   Energy services..........   -.2  -1.5   -.5  -1.0    .2   -.6    .5     -3.0
    Electricity.............    .3  -1.1    .0  -1.2    .2   -.4    .3      -.6
    Utility (piped) gas                                                        
       service..............  -2.0  -2.7  -2.6    .0    .3  -1.4   1.2    -11.5
  All items less food and                                                      
     energy.................    .2    .2    .3    .1    .2    .1    .1      1.8
   Commodities less food and                                                   
      energy commodities....    .2    .3    .1   -.1   -.1   -.1   -.1      -.5
    New vehicles............    .2    .2    .1    .2    .1   -.2    .0       .6
    Used cars and trucks....   1.0   1.2    .6   -.4   -.4   -.6   -.4     -1.5
    Apparel.................    .3    .5   -.3   -.5   -.1    .3    .3      -.9
    Medical care commodities    .7    .1    .1    .4    .0    .1    .3      3.4
   Services less energy                                                        
      services..............    .1    .2    .3    .2    .3    .2    .1      2.6
    Shelter.................    .2    .3    .3    .2    .3    .4    .2      3.1
    Transportation services     .3    .0    .1    .7    .4   -.2   -.3      2.1
    Medical care services...   -.2    .4    .9    .2   -.2    .1    .0      2.2

   1 Not seasonally adjusted.

 Consumer Price Index Data for August 2015


 The food index increased 0.2 percent in August, the same increase as in
 July. The index for food at home advanced 0.3 percent, also the same
 increase as the prior month. Major grocery store food group indexes were
 mixed in August. The largest increase was the fruits and vegetables index,
 which rose 1.5 percent with both fresh fruits and fresh vegetables posting
 their largest increases of the year. The index for meats, poultry, fish,
 and eggs also increased, rising 0.5 percent. The indexes for beef,
 poultry, and pork all declined, but the eggs index rose 7.7 percent and
 is now up 35.3 percent over the past year. The index for nonalcoholic
 beverages rose for the third month in a row, increasing 0.1 percent. The
 other three groups all turned down in August after rising in July. The
 index for dairy and related products fell 0.3 percent, the index for
 other food at home declined 0.2 percent, and the cereals and bakery
 products index decreased 0.1 percent. The index for food at home has risen
 0.8 percent over the  past 12 months, with only the dairy group showing a
 decline over that span. The index for food away from home, which was
 unchanged in July, increased 0.2 percent in August and has risen 2.7
 percent over the past 12 months.   


 The energy index fell 2.0 percent in August after rising in five of the
 past 6 months. The gasoline index, which had risen 3 months in a row, fell
 4.1 percent in August. (Before seasonal adjustment, gasoline prices
 declined 5.4 percent in August.) The fuel oil index also declined,
 falling 8.1 percent, its third straight decrease. The index for natural
 gas rose, however, increasing 1.2 percent after a 1.4 percent decline in
 July. The electricity index also turned up, rising 0.3 percent in August
 after declining in July. All the major energy components have declined
 over the past 12 months. The electricity index has fallen 0.6 percent,
 while the others have declined more sharply; the fuel oil index has
 decreased 34.6 percent, the index for gasoline has declined 23.3 percent,
 and the index for natural gas has fallen 11.5 percent. 
 All items less food and energy
 The index for all items less food and energy increased 0.1 percent in
 August, as it did in July. The shelter index was the main source of the
 increase; it rose 0.2 percent in August following a 0.4 percent increase
 in July. The rent index rose 0.3 percent in August, the same increase as
 in July, while the index for owners' equivalent rent increased 0.2 percent.
 The index for lodging away from home, however, turned down in August,
 falling 0.6 percent after a 2.5 percent increase the prior month. The
 apparel index increased 0.3 percent in August, the same increase as last
 month. The tobacco index also rose in August, increasing 0.5 percent, and
 the index for alcoholic beverages advanced 0.1 percent. The medical care
 index was unchanged in August, with the indexes for hospital services and
 prescription drugs rising but the indexes for physicians' services and
 nonprescription drugs declining. The new vehicles index was unchanged in
 August, as was the index for personal care. Several indexes declined in
 The index for airline fares fell 3.1 percent after decreasing 5.6 percent
 in July. The index for used cars and trucks decreased 0.4 percent, its
 fourth decline in a row. The index for household furnishings and
 operations declined 0.3 percent, and the recreation index fell 0.1

 The index for all items less food and energy has risen 1.8 percent over
 the past 12 months; the 12-month change has been 1.8 percent in five of
 the last 6 months. The indexes for shelter, medical care, new vehicles,
 recreation, and tobacco are among the indexes that have increased over
 the past year. In contrast, the indexes for airline fares, apparel, used
 cars and trucks, and household furnishings and operations have all
 declined over the last 12 months.  

 Not seasonally adjusted CPI measures

 The Consumer Price Index for All Urban Consumers (CPI-U) increased 0.2
 percent over the last 12 months to an index level of 238.316
 (1982-84=100). For the month, the index declined 0.1 percent prior to
 seasonal adjustment.  

 The Consumer Price Index for Urban Wage Earners and Clerical Workers
 (CPI-W) decreased 0.3 percent over the last 12 months to an index level
 of 233.366 (1982-84=100). For the month, the index declined 0.2 percent
 prior to seasonal adjustment.  

 The Chained Consumer Price Index for All Urban Consumers (C-CPI-U)
 decreased 0.1 percent over the last 12 months. For the month, the index
 declined 0.2 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 September 2015 is scheduled to be released
 on Thursday, October 15, at 8:30 a.m. (EDT). 

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 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 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 2013."  These data are available on the CPI home page
 (, or by using the following link:   

 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


 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 January, 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
 ( and the Timeline of Seasonal Adjustment
 Methodological Changes ( 
 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
 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. 
 2015 Series Adjusted Using Intervention Analysis Seasonal Adjustment
 For the seasonal factors introduced in January 2015, BLS adjusted 33
 series using Intervention Analysis Seasonal Adjustment, including
 selected food and beverage items, motor fuels, electricity and vehicles.
 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 2015,
 revised seasonal factors and seasonally adjusted indexes for 2009-2014
 were calculated and published. For directly adjusted series, the seasonal
 factors for 2014 will be applied to data for 2015 to produce the
 seasonally adjusted 2015 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 82
 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. Thirty-two of the 82
 components of the U.S. city average all items index are not seasonally
 adjusted for 2015.
 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 Christopher Graci, Justin
 Yarros, or Samuel An at (202) 691-6968 or by e-mail at, or
 If you have general questions about the CPI, please call our information
 staff at (202) 691-7000. 

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Last Modified Date: September 16, 2015