Industry classification of firms is currently based on the 2012 North American Industry Classifcation System (NAICS), which is comprised of nearly 1,200 industries. For more information on the 2012 NAICS codes, as well as comparisons between the 2007 and 2012 codes, go to http://www.census.gov/eos/www/naics/
. Data for nonemployers generally are provided at broader levels of industry detail than data for employers. Nonemployer Statistics are limited to approximately 450 codes that are available through administrative-record sources and are common to all three legal forms of organization applicable to nonemployer businesses (sole proprietorship, partnership, and corporation). These industry codes are primarily self-classified by tax filers through Internal Revenue Service forms. Other sources for assigning industry classifications are the Social Security Administration and the Bureau of Labor Statistics.
There is a small percentage of nonemployers that are unclassified. The percentage is at its lowest in Economic Census years. For these cases, an industry classification is assigned, or imputed, from a classified firm within the same county with a similar value of receipts and the same legal form of organization. This imputation procedure has the effect of preserving the distribution of firms and receipts by industry, while eliminating an unclassified component which varies in size each year. To control the contribution of imputed classifications, we have adopted the rule that if firms with an imputed classification account for more than 40 percent of either receipts or number of firms in a published row, both items are suppressed and assigned a flag of `S`. At the national level, less than 12 percent of nonemployer firms have an imputed classification, accounting for 3 to 5 percent of receipts.
The Nonemployer Statistics series includes the following NAICS sectors:
||Agricultural Support, Forestry, Fishing, and Hunting
||Transportation and Warehousing
||Finance and Insurance
||Real Estate and Rental and Leasing
||Professional, Scientific, and Technical Services
||Administrative and Support and Waste Management and Remediation Services
||Health Care and Social Assistance
||Arts, Entertainment, and Recreation
||Accommodation and Foodservices
||Other Services (except Public Administration)
NAICS Industries Excluded or Reclassified
Nonemployer Statistics cover most NAICS industries within the above listed sectors, however, there are some exclusions. The following sectors are not published as part of the Nonemployer Statistics data: crop and animal production (NAICS 111,112), National postal service (NAICS 491), Investments, funds, trusts, and other financial vehicles (NAICS 525), Management of companies and enterprises (NAICS 55), private households (NAICS 814), and Public administration (NAICS 92).
Certain industries are automatically reclassified when they appear in the Nonemployer universe because these industries are generally assumed to require employees. These include: New car dealers (44111) -- reclassified to Used car dealers (44112); Department stores (4521) -- reclassified to General merchandise stores (452); Rail transportation (NAICS 482) -- reclassified to Support activities for transportation (488); Hospitals (NAICS 622) -- reclassified to Other ambulatory health care services (6219); and finally Oil and gas extraction (2111) only in areas without oil or gas production -- reclassified to Other financial investment activities (5239).