WASHINGTON: The Consumer Price Index for All Urban Consumers (CPI-U) increased 0.3 percent in April on a seasonally adjusted basis after rising 1.2 percent in March, the U.S. Bureau of Labor Statistics reported today. Over the last 12 months, the all items index increased 8.3 percent before seasonal adjustment.
Increases in the indexes for shelter, food, airline fares, and new vehicles were the largest contributors to the seasonally adjusted all items increase. The food index rose 0.9 percent over the month as the food at home index rose 1.0 percent. The energy index declined in April after rising in recent months. The index for gasoline fell 6.1 percent over the month, offsetting increases in the indexes for natural gas and electricity.
The index for all items less food and energy rose 0.6 percent in April following a 0.3-percent advance in March. Along with indexes for shelter, airline fares, and new vehicles, the indexes for medical care, recreation, and household furnishings and operations all increased in April.
The indexes for apparel, communication, and used cars and trucks all declined over the month.
The all items index increased 8.3 percent for the 12 months ending April, a smaller increase than the 8.5-percent figure for the period ending in March. The all items less food and energy index rose 6.2 percent over the last 12 months. The energy index rose 30.3 percent over the last year, and the food index increased 9.4 percent, the largest 12-month increase since the period ending April 1981.
The food index increased 0.9 percent in April; this was its seventeenth consecutive monthly increase. The index for food at home rose 1.0 percent after rising 1.5 percent the prior month.
Five of the six major grocery store food group indexes increased over the month. The index for dairy and related products rose 2.5 percent, its largest monthly increase since July 2007. The index for nonalcoholic beverages also rose sharply, increasing 2.0 percent over the month. The index for meats, poultry, fish, and eggs rose 1.4 percent as the index for eggs increased 10.3 percent in April.
The index for cereals and bakery products increased 1.1 percent over the month, and the index for other food at home rose 0.7 percent. In contrast to these increases, the index for fruits and vegetables declined in April, falling 0.3 percent. The index for fresh fruits declined 0.5 percent, while the index for fresh vegetables was unchanged.
The food away from home index rose 0.6 percent in April after rising 0.3 percent in March. The index for full service meals rose 0.9 percent over the month. The index for limited service meals increased 0.3 percent in April after declining in March.
The food at home index rose 10.8 percent over the last 12 months, the largest 12-month increase since the period ending November 1980. The index for meats, poultry, fish, and eggs increased 14.3 percent over the last year, the largest 12-month increase since the period ending May 1979.
The other major grocery store food group indexes also rose over the past year, with increases ranging from 7.8 percent (fruits and vegetables) to 11.0 percent (other food at home).
The index for food away from home rose 7.2 percent over the last year. The index for full service meals rose 8.7 percent over the last 12 months, the largest 12-month increase since the inception of the index in 1997. The index for limited service meals rose 7.0 percent over the last year, while the index for food at employee sites and schools fell 30.0 percent, reflecting widespread free lunch programs.
The energy index declined 2.7 percent in April after rising 11.0 percent in March. The gasoline index declined in April, falling 6.1 percent after increasing 18.3 percent the prior month.
(Before seasonal adjustment, gasoline prices fell 1.0 percent in April.) The other major energy component indexes increased in April; the index for natural gas rose 3.1 percent and the index for electricity increased 0.7 percent.
The energy index rose 30.3 percent over the past 12 months. All the major energy component indexes increased over the year. The gasoline index increased 43.6 percent and the fuel oil index rose 80.5 percent. The index for electricity rose 11.0 percent, and the index for natural gas increased 22.7 percent over the last 12 months.
All items less food and energy
The index for all items less food and energy rose 0.6 percent in April. The shelter index increased 0.5 percent in April, the same increase as in March. The rent index rose 0.6 percent and the owners’ equivalent rent index rose 0.5 percent. The index for lodging away from home continued to increase, rising 1.7 percent in April after advancing 3.3 percent in March.
The index for airline fares continued to rise sharply, increasing 18.6 percent in April, the largest 1-month increase since the inception of the series in 1963. The index for new vehicles increased 1.1 percent in April after rising 0.2 percent in March. The medical care index increased 0.4 percent in April. The index for hospital services rose 0.5 percent over the month, the index for physicians’ services rose 0.2 percent, and the index for prescription drugs was unchanged.
The recreation index rose 0.4 percent in April after increasing 0.2 percent in March. The index for household furnishings and operations continued to increase, rising 0.4 percent in April after increasing 1.0 percent the prior month. The index for motor vehicle insurance increased 0.8 percent in April. Also rising over the month were the indexes for personal care (+0.4 percent), education (+0.2 percent), alcoholic beverages (+0.4 percent), and tobacco (+0.4 percent).
A few major component indexes declined in April. The apparel index fell 0.8 percent over the month, ending a string of six consecutive increases. The index for communication fell 0.4 percent in April, its third consecutive monthly decline. The index for used cars and trucks also fell 0.4 percent over the month, its third straight decline after a long series of increases.
The index for all items less food and energy rose 6.2 percent over the past 12 months. Virtually all major components have increased over the span. The shelter index rose 5.1 percent over the last year, and the medical care index increased 3.2 percent. Several transportation indexes show notable increases including used cars and trucks (+22.7 percent) and new vehicles (+13.2 percent).
The index for airline fares rose 33.3 percent over the last year, the largest 12-month increase since the period ending December 1980.
Not seasonally adjusted CPI measures
The Consumer Price Index for All Urban Consumers (CPI-U) increased 8.3 percent over the last 12 months to an index level of 289.109 (1982-84=100). For the month, the index increased 0.6 percent prior to seasonal adjustment.
The Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W) increased 8.9 percent over the last 12 months to an index level of 284.575 (1982-84=100). For the month, the index rose 0.5 percent prior to seasonal adjustment.
The Chained Consumer Price Index for All Urban Consumers (C-CPI-U) increased 7.8 percent over the last 12 months. For the month, the index increased 0.6 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 May 2022 is scheduled to be released on Friday, June 10, 2022 at 8:30 a.m. (ET).
Brief Explanation of the CPI
The Consumer Price Index (CPI) measures the change in prices paid by consumers for goods and services. The CPI reflects spending patterns for each of two population groups: all urban consumers and urban wage earners and clerical workers. The all urban consumer group represents about 93 percent of the total U.S. population. It is based on the expenditures of almost all residents of urban or metropolitan areas, including professionals, the self-employed, the poor, the unemployed, and retired people, as well as urban wage earners and clerical workers. Not included in the CPI are the spending patterns of people living in rural nonmetropolitan areas, farming families, people in the Armed Forces, and those in institutions, such as prisons and mental hospitals. Consumer inflation for all urban consumers is measured by two indexes, namely, the Consumer Price Index for All Urban Consumers (CPI-U) and the Chained Consumer Price Index for All Urban Consumers (C-CPI-U).
The Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W) is based on the expenditures of households included in the CPI-U definition that meet two requirements:
more than one-half of the household’s income must come from clerical or wage occupations, and at least one of the household’s earners must have been employed for at least 37 weeks during the previous 12 months. The CPI-W population represents about 29 percent of the total U.S. population and is a subset of the CPI-U population.
The CPIs are based on prices of food, clothing, shelter, fuels, transportation, doctors’ and dentists’ services, drugs, and other goods and services that people buy for day-to-day living. Prices are collected each month in 75 urban areas across the country from about 6,000 housing units and approximately 22,000 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 75 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 visit, telephone call, or web collection by the Bureau’s trained representatives.
In calculating the index, price changes for the various items in each location are aggregated using 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 23 selected 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. The CPI-U and CPI-W are considered final when released, but the C-CPI-U is issued in preliminary form and subject to three subsequent quarterly revisions.
The index measures price change from a designed reference date. For most of 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 7 percent from the reference base, for example, is shown as 107.000. Alternatively, that relationship can also be expressed as the price of a base period market basket of goods and services rising from $100 to $107.
Sampling Error in the CPI
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 0.03 percent for the U.S. all items CPI. 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 percent of these estimates will be within 0.06 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-U, we are 95 percent confident that the actual percent change based on all retail prices would fall between 0.14 and 0.26 percent. For the latest data, including information on how to use the estimates of standard error, see www.bls.gov/cpi/tables/variance-estimates/home.htm.
Calculating Index Changes
Movements of the indexes from 1 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 following table shows an example of using index values to calculate percent changes:
Item A Item B Item C
Year I 112.500 225.000 110.000
Year II 121.500 243.000 128.000
Change in index points 9.000 18.000 18.000
Percent change 9.0/112.500 x 100 = 8.0 18.0/225.000 x 100 = 8.0 18.0/110.000 x 100 = 16.4
Use of Seasonally Adjusted and Unadjusted Data
The Consumer Price Index (CPI) produces both unadjusted and seasonally adjusted 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 weather events, 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.
The Bureau of Labor Statistics uses intervention analysis seasonal adjustment (IASA) 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.
For example, this procedure was used for the motor fuel series to offset the effects of the 2009 return to normal pricing after the worldwide economic downturn in 2008. Retaining this outlier data during seasonal factor calculation would distort the computation of the seasonal portion of the time series data for motor fuel, so it was estimated and removed from the data prior to seasonal adjustment. Following that, seasonal factors were calculated based on this “prior adjusted” data. These seasonal factors represent a clearer picture of the seasonal pattern in the data. The last step is for motor fuel seasonal factors to be applied to the unadjusted data.
For the seasonal factors introduced for January 2022, BLS adjusted 72 series using intervention analysis seasonal adjustment, including selected food and beverage items, motor fuels, electricity, and vehicles.
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 5 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 5 years of data. Seasonally adjusted indexes beyond the last 5 years of data are considered to be final and not subject to revision. For January 2022, revised seasonal factors and seasonally adjusted indexes for 2017 to 2021 were calculated and published. For series which are directly adjusted using the Census X-13ARIMA-SEATS seasonal adjustment software, the seasonal factors for 2021 will be applied to data for 2022 to produce the seasonally adjusted 2022 indexes. Series which are indirectly seasonally adjusted by summing seasonally adjusted component series have seasonal factors which are derived and are therefore not available in advance.
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 5 years, but the seasonally adjusted indexes before that period will not be changed. For 2022, 22 of the 81 components of the U.S. city average all items index are seasonally adjusted.