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Consumer Price Index
Bureau of Labor Statistics > Consumer Price Index > Data > Research

CPI Size Change Research Index: R-CPI-SC

Background

Building on the February 2023 Beyond the Numbers (BTN) article “Getting less for the same price? Explore how the CPI measures "shrinkflation" and its impact on inflation”, BLS has created a series of research indexes to estimate the impact of downsizing and upsizing in the CPI beginning with December 2014 data called the CPI size change research index (R-CPI-SC). These research indexes are calculated by imputing price changes in the month a product size change occurs for a product active in the CPI sample, instead of using its observed price change.

BLS monitors the frequency of downsizing and upsizing in the CPI sample as described in the February 2023 Beyond the Numbers (BTN) article. These data are also available below.

Limitations

CPI research series differ from the official indexes in their purpose, scope, formulas, or grouping. These research series also may have larger measurement error than the official published indexes. BLS sometimes revises research indexes to incorporate information that was not available when the indexes were first published. Customers should be aware of the limitations of these products.

The CPI sample is designed to measure average change over time in the prices paid by the urban consumers for a market basket of material goods and services. The CPI sample is not scientifically designed specifically to measure upsizing and downsizing frequencies in the marketplace.

Although the methodology used to create the counts and indexes is similar to that of the article, some modifications have been incorporated to facilitate on-going estimation and analysis. Users should be aware that data from earlier time periods does not exactly reproduce the results presented in the article.

Available data

The monthly time series data will be released on a quarterly schedule, with releases occurring in January, April, July, and October. Release of data may be delayed due to resource availability and other constraints.

Research indexes are available for food at home, all item strata within food at home, and a select group of additional item strata that have had downsizing or upsizing observed since 2015.  Additional aggregate indexes may be added later depending on resource availability and other constraints.

Data

  • R-CPI-SC, December 2014-present (XLSX)

  • R-CPI-SC, Frequency of downsizing and upsizing, January 2015-present (XLSX)

Related Articles

Additional information on downsizing and upsizing in the CPI is available in the Beyond the Numbers article Getting less for the same price? Explore how the CPI measures "shrinkflation" and its impact on inflation.

Last Modified Date: April 15, 2025