Hi y’all. I have a question regarding the codes for industry (IND) and NAICS industry (INDNAICS) . I noticed that some of the 6-digit industries are available (for example, 443141->Household appliance stores, 517311 ->Wired telecommunications carriers, and 812112->Beauty salons) but others are not there (like, 334417->Electronic Connector Manufacturing, 483113-Coastal and Great Lakes Freight Transportation, and 551111->Offices of Bank Holding Companies). Just wondering if anybody knows why some of the 6-digit industries are missing there? Thank you.
The Census Bureau uses its own industry classification system to code its industries. It is based on NAICS, but has less detail. INDNAICS is a recode of the Census Bureau industry coding, and so it has less detail than the original NAICS system. Your second link shows the correspondence between Census industry codes (IND) and INDNAICS codes. When an INDNAICS code has fewer than 6 digits, that means it represents a higher level of aggregation. For example, INDNAICS code 3254 is “Pharmaceutical and Medicine Manufacturing”, which covers the 6-digit industries 325411, 325412, 325413, and 325414 (you can see the details of these here). When an INDNAICS code has a letter in it, the meaning is described in the legend at the top of the table. For example, code 2213M covers all 6-digit industries starting with 2213 (except 22132, which has its own code).
Sometimes you cannot tell all the 6-digit industries contained within an INDNAICS code just by looking at the code. For example, it is not clear which industries are in code 334M1 vs 334M2. You can find all the details of this using the crosswalks on the Census Bureau website. Using the “Census 2012 Detailed Industry Code List” we can see that 334M1 (aka IND code 3370) contains NAICS codes 3342 and 3343, while 334M2 (aka IND code 3390) contains NAICS codes 3344 and 3346.