Concentration Ratios

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Concentration Ratios

The following data are from the Economic Census.  All of these reports classify industries by the percent of output accounted for by the largest 4, 8, 20 and 50 companies.  Only the manufacturing reports include the Herfindahl-Hirschman Index.  Data for 2002 and 1997 are organized and classified by the North American Industry Classification System (NAICS).  Data for 1992 and prior years are organized and classified by the Standard Industry Classification (SIC) system.

Concentration data from the 2007 Economic Census are expected to be published by sector between October 2010 and July 2011.

2002 and 1997 Economic Censuses, by NAICS

With the exception of data for manufacturing, these data are from Table 6 in reports entitled Establishment and Firm Size. These tables are also available in manipulable form on DVD-ROM (2002) or CD-ROM (1997) and in American FactFinder.

NAICS	Sector title	2002 Economic Census		1997 Economic Census
		Link to PDF	Link to FactFinder	Link to PDF	Link to FactFinder
21	Mining	No concentration data available
22	Utilities
23	Construction (none available)	No concentration data available
31-33	Manufacturing		Choose Value of Shipments or Value Added		Choose Value of Shipments or Value added
42	Wholesale Trade
44-45	Retail Trade
48-49	Transportation and Warehousing
51	Information
52	Finance and Insurance
53	Real Estate and Rental and Leasing
54	Professional, Scientific, and Technical Services
55	Management of Companies and Enterprises (none available)	No concentration data available
56	Administrative and Support and Waste Management and Remediation Services
61	Educational Services
62	Health Care and Social Assistance
71	Arts, Entertainment and Recreation
72	Accommodation and Foodservices
81	Other Services (except Public Administration)

1992 Economic Census, by SIC
 

Report #	Sector title	Link to PDF or text
MC92-S-2	Concentration Ratios in Manufacturing	ASCII text
The following are extracted from "1992 Economic Census Establishment and Firm Size" reports.
FC92-S-1	1992 Census of Financial, Insurance and Real Estate Industries (1 Mb)
RC92-S-1	1992 Census of Retail Trade(.9 Mb)
SC92-S-1	1992 Census of Service Industries (4 Mb)
UC92-S-1	1992 Census of Transportation, Communications, and Utilities (2 Mb)
WC92-S-1	1992 Census of Wholesale Trade (4 Mb)

Concentration data are not available for mining and construction.

1987 and Earlier Years

Manufacturing. This spreadsheet [xls], adapted from a file originally published on the 1992 Economic Census CD-ROM, contains data for Concentration Ratios in Manufacturing for each particular SIC-based industry back as far as the time series is unaffected by definitional changes, in some cases to 1947. Data for 1982 and earlier years for those SICs that changed in 1987 are available only in Concentration Ratios reports that may still be retained at major libraries.

Retail Trade, Wholesale Trade, and Service Industries. The 1987 Economic Census CD-ROM 1E includes a file for each of these three sectors with concentration data for 1987 only. Data for earlier years are available only in printed reports that may still be retained at major libraries.

To order CD-ROMs, see http://www.census.gov/mp/www/cat/business_and_industry.