The Consumer Price Index: Data Quality
August 18, 2025
Questions have recently arisen surrounding the reliability and usefulness of certain federally produced
data, including the Consumer Price Index (CPI). The President’s recent removal of the head of the Bureau
of Labor Statistics (BLS, which produces the CPI) as well as the President’s FY2026 budget proposal,
which would further reduce BLS staffing levels, have brought renewed interest to the topic. The CPI is
one of the leading measures of U.S. consumer inflation and is tracked closely by both private and public
actors. New CPI data may affect consumption, financial market, and policy decisions. Given the
widespread use of the CPI, it is important to the U.S. economy that it be timely, accurate, and trusted.
This Insight covers what the CPI is and how it is measured, recent changes to CPI data collection and
methodology, and longer-term trends in response rates.
CPI Methodology
BLS is a statistical agency housed within the Department of Labor. It publishes CPI data on a monthly
basis, including series for all urban consumers as well as wage and clerical workers. (A chained index is
also produced with a lag.) Data breakdowns are available by expenditure category and geographic detail.
BLS creates the CPI using several surveys:
• The decennial Census provides population data used to create the geographic sample of
the CPI.
• The Consumer Expenditure Surveys provide expenditure data used to create the “market
basket” of goods and services for which prices are collected and weight those expenditure
categories based on average spending patterns.
• Surveys on prices provide the data used to calculate how prices have changed from one
month to the next. BLS uses two different surveys, one in which roughly 100,000 prices
per month are collected for commodities and services and another in which roughly 8,000
rental housing unit quotes are collected for all housing.
BLS personnel collect most price data via personal visit or phone, but some commodities and services
prices are obtained on websites and apps or from secondary sources.
