Dear IPUMS team,
I was looking into the CPS files from 1992 to 2002 and notice that three occupations completely vanish after August 1995 (never appearing again). Those are:
Occ 3 - Legislators
Occ 16 - Postmasters and superintendents
Occ 169 - Judges
I assumed that they were probably simply being coded as something else; however, I investigated similar occupations (such as postal office clerks, lawyers, etc.) and none displayed a spike in the number of observations after August 1995.
Is there any explanation for this?
While I understand the major sample redesign undergone by the CPS during that time, it is unclear why such codes simply stopped appearing - even in later years.
The CPS uses the Census occupation classification scheme to report occupations; IPUMS offers these via the OCC variable without modification or recoding. See the OCC codes section for links to the sample-specific occupation codes. Note that our code lists reflect the documentation that accompanies the Census Bureau’s release of CPS data; it is possible that some codes listed may not be present in the data.
The September 1995 CPS codebook states on page 6-1 that beginning with this month, “codes 003 and 016 (legislators and postmasters, respectively) are collapsed into Code 022, (managers and administrators, N.E.C.). Also, Code 179, (judges) was collapsed into Code 178, (lawyers).”
Later samples treat these occupations differently, and they are sometimes identifiable with their own codes, or labeled more clearly as part of other occupation codes that include multiple occupations. In some cases, an occupation may have its own associated code in the original CPS codebook or data dictionary, but no person records in the public use data have that occupation code. This could occur if the Census Bureau takes steps to protect respondent privacy when there are very small numbers of respondents with a particular occupation code.