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Quarterly Services Survey 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, and
  • redistribute burden for small and medium size businesses

The current Quarterly Services Survey sample was introduced with the release of estimates for the fourth quarter of 2012 on March 7, 2013.

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 19,000 employer firms.  The size of the previous Quarterly Services Survey sample was approximately 17,000 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

What is the impact of adopting the 2007 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.  Prior to the March 2013 release for fourth quarter of 2012, Quarterly Services Survey estimates were published on a 2002 NAICS basis.  Currently, Quarterly Services Survey estimates are published on a 2007 NAICS basis.

The changes between 2002 NAICS and 2007 NAICS that affect industries within the scope of the Quarterly Services Survey are summarized below.

  • Sector 51, Information- Telecommunications Resellers and Cable and Other Program Distribution were moved, Internet Service Providers and Web Search Portals industries were restructured, and a new six-digit industry was created in Other Information Services subsector.
  • Sector 53, Real Estate and Rental and Leasing- 2002 NAICS code 525390- Real Estate Investment Trusts, was deleted and portions of it were reclassified as follows: (1) Equity REITs is classified in the Real Estate subsector in NAICS Industry Group 5311- Lessors of Real Estate, under individual national industries based on the content of the portfolio of real estate operated by a particular REIT; and (2) Mortgage REITs is moved to NAICS 525990, Other Financial Vehicles.
  • Sector 54, Professional, Scientific, and Technical Services - Research and Development in Biotechnology was added as a 6-digit industry.
  • Sector 56, Administrative and Support and Waste Management and Remediation Services - Establishments that primarily provide executive search consulting services were moved to a new 6-digit industry, Executive Search Services.

For a more detailed comparison between the 2002 and 2007 NAICS, please see the NAICS Concordance Tables.

Source: U.S. Census Bureau | Services | (888) 211-5946 |  Last Revised: March 11, 2015