There are several different sources for data on business and industry discussed here.

Industries are classified using the North American Industry Classification System (NAICS).  NAICS is the standard used by Federal statistical agencies in classifying business establishments for the purpose of collecting, analyzing, and publishing statistical data related to the U.S. business economy. NAICS is a 2- through 6-digit hierarchical classification system, offering five levels of detail. Each digit in the code is part of a series of progressively narrower categories, and the more digits in the code signify greater classification detail.

Economic data is subject to suppression. The Census Bureau is committed to confidentiality and constantly pursues new procedures, technologies, and methodologies to safeguard individual data. Disclosure avoidance is the process for protecting the confidentiality of data. Cell suppression protects the confidentiality of individual businesses by replacing cell values with symbols in tables, where the amount of the cell if it were known, would allow one to estimate a single contributor’s value too closely. This occurs when there are very few contributors, or when there are one or two large contributors that dominate the aggregate statistic.

Find more economic data in the Labor Force topic.