- Emsi combines all industry data under 111 (Crop Production) and 112 (Animal Production) into single detailed codes: 111000 and 112000, respectively. This is due to the paucity of detailed and complete agricultural employment data, as well as for compatibility with categories used in Input-Output modeling.
- Emsi uses a single code, 482110 (Rail Transportation), as an aggregate of NAICS 482111 and 482112.
- In Emsi data, 491110 (Postal Service) represents private-sector United States Postal Service (USPS) contractors only. Actual USPS establishments are found in Emsi code 901149.
- Emsi does not have data for 541120 (Offices of Notaries), because the BLS does not report any data for that category.
- Emsi creates a separate hierarchy for public-sector establishments under code 90 (Government), as explained below.
NAICS is intended to classify an establishment’s activity regardless of its ownership (public or private sector) or legal form of organization (proprietorship, partnership, corporation, for-profit, nonprofit, etc.). However, due to the realities of available data, Emsi treats establishments with public and private sector ownership differently. In Emsi data, all establishments in the main NAICS hierarchy are private-sector only — including 611 (Educational Services) and 62 (Health Care and Social Assistance). Thus, Emsi does not use the standard NAICS classification in code 92 (Public Administration). This handling is similar to Current Employment Statistics (CES), Occupational Employment Statistics (OES), and BEA data sources. QCEW is the major data source that does use code 92, because QCEW includes an “ownership code” (private, federal, state, local) in addition to an industry code.