Quarterly Services Survey - Sample Revision FAQs

What is a sample revision and why is it necessary?

A sample revision is the process used to re-design and re-select the samples for many of the Census Bureau’s surveys of the retail, wholesale, and service industries. This process is performed to

ensure each sample is representative of its target population
improve the efficiency of each sample
incorporate updates to the industry classification structure
expand industry coverage of the survey
update questions and instructions to obtain more accurate data
redistribute burden for small and medium size businesses

The current Quarterly Services Survey sample was introduced with the release of estimates for the third quarter of 2017 on November 17, 2017.

How often is a sample revision performed for the Quarterly Services Survey?

Sample revisions are performed approximately every 5 to 7 years. During the period for which the samples are used, updates are made on a quarterly basis to reflect changes in the business universe. These updates are designed to account for new businesses (births) and businesses which discontinue operations (deaths). The samples are also updated to reflect mergers, acquisitions, divestitures, splits, and other changes to the business universe.

What is the size of the Quarterly Services Survey sample?

The size of the current Quarterly Services Survey sample is approximately 19,500 employer firms.

Are the estimates from different Quarterly Services Survey samples comparable?

In most cases, yes. Whenever possible, estimates from different samples have been put on a comparable basis. For a detailed description of the process used to link the estimates from different samples and for specific information on which industry estimates are not comparable, please refer to https://www.census.gov/services/qss/technical_documentation.html.

What is the impact of adopting the 2017 North American Industry Classification System (NAICS) definitions for the Quarterly Services Survey?

NAICS is scheduled to be reviewed every 5 years for potential revisions, so that the classification system can keep pace with the changing economy. Currently, Quarterly Services Survey estimates are published on a 2017 NAICS basis. Prior to the February 2025 advance release for fourth quarter 2024, Quarterly Services Survey estimates were published on a 2012 NAICS basis. Changes between 2012 and 2017 NAICS have no impact on the Quarterly Services Survey estimates.

For a more detailed comparison between the 2012 and 2017 NAICS, please see the NAICS Concordance Tables.