I was checking documentation regarding the CPS coding break between 1992 and 2003 and came across this section of the BLS website: https://www.bls.gov/cps/cpsoccind.htm.
There, it is said that the BLS created its own Crosswalk with conversion rates connecting Census 1990 to Census 2000 occupations. It is said that:
“BLS created conversion factors between the 1990 and 2002 Census classifications. These factors are based on 3-year average survey microdata (2000–2002) that were dual-coded to both the old and new classification systems. They are tabulated at the major group level as well as by the detailed classifications.”
My questions are the following:
1 - The conversion rates are reported in PDF tables, with one page being allocated to each Census 1990 occupation. Translating this by hand to a unique table with occupation codes is cumbersome, so I was wondering if by any chance you also happen to have an excel version of it (or something of the sort). That would be of great help! The tables I have in mind are tables 5 and 6 from the aforementioned link.
2 - Another question refers to the methodological approach. This table is strikingly different from the Census’ own Conversion rates. For instance, 1990 occupation 04 “Chief executives & general administrators, public administration” displays only 2 links in the Census crosswalk, but more than 10 in the BLS one (https://www.bls.gov/cps/detocc19902002.pdf). What are the sources of those differences? I understand that the process through which both crosswalks were assembled are different (with the Census double-coding a sample from the year of 1990), but the discrepancy is still stark. If possible, could you kindly try to elucidate why this is the case, please?
My apologies for the lengthy message and thanks in advance for your time!
As you suggest, the discrepancy between the Census Bureau’s and the Bureau of Labor Statistics’ (BLS) conversation rates is driven by their different methods.
The technical report preceding the Census crosswalk in this working paper (Scopp, 2003) explains that “the crosswalks presented in this paper attempt to merge the best of both methods”, the methods being: (a) examining occupation/industry titles for “ideal” changes, and (b) individually double coding a sample of respondents into both the 1990 and 2000 industry and occupation classifications.
The Census crosswalks start from a list of “legitimate 1990-2000 code combinations” based on their appearance in the index title crosswalk. Census Bureau researchers then re-coded a sample of respondents from the 1990 census to the 2000 census codes using the provided description of the respondent’s job (or if unemployed, their most recent job held in the 5 years prior to the Census). Note that no double surveying of respondents occurred; the codes were allocated logically based on a review of the job description. The percent of each reported code combination in the double coded sample then drove the conversion factors within the allowable combinations. Some additional combinations not in the index that were later deemed legitimate were re-added, but double coded combinations that were deemed the result of coding error were eliminated.
The method used in the BLS conversion factor tables that you link to is briefly summarized in a note preceding the tables. It states that the factors “are based on 3-year average survey microdata (2000-2002) that were dual-coded” and that the tables report “the percent distribution of employment re-coded from one classification system to another.” Moreover, the BLS states that the “conversion factors incorporate classifications that were allocated or, on occasion, mis-assigned.” There is no suggestion that double-coded conversation rates were restricted to a matrix of legitimate values as in the Census Bureau’s crosswalk. The cautionary note regarding misassignment further suggests that cases were not discarded based on suspected miscoding. This likely drives the larger number of cross-walked occupation code combinations in the BLS crosswalk.
We do not have a digitized version of these BLS crosswalks. However, you may try reaching out to the BLS directly to see if they may have this data and can share it.