Concentration Ratios
The
Concentration Ratio indicates what proportion of a line of business is held by the top 4, 8, 20 and 50 companies, respectively. Names of the companies in these categories are not provided in this data. The Concentration Ratio is organized in NAICS order so you may have to use a
conversion chart if you know only the SIC number.
Databases
http://www.census.gov/epcd/www.concentration.html
How to
Printed Sources
Concentration Ratios for 1992 (SuDocs#: C3.24/12=MC91-S2) and 1987 (SuDocs#: C3.24/12:MC 87-S-6) are available in the Government Documents Room (Queens Library 4th Floor). The 1997 and 2002 ratios appear to be available only electronically at the above link.
How to
Reviewed: August 3 2005
