I want to group occupational codes based on the 1990 classification system (occ1990) into slightly more aggregated categories (not a highly aggregated system based on one digit, but perhaps two digits). Is there an established document that allows me to do that systematically?
One reasonable way to aggregate these codes is to use the occupation headings as listed on the codes tab. That is, OCC1990==003 - 022 are Executive, Administrative, and Managerial Occupations, OCC1990==023 - 037 are Management Related Occupations, etc. I’m not sure if this sort of aggregation is exactly what you are looking for, but it is a fairly reasonable approach.