Discrepancies between IPUMS-CPS metarea and 1990 census delineation file?

Documentation and prior questions have pointed users to the Census Bureau’s historical delineation file (1990) to provide a county-MSA crosswalk for the METAREA variable in IPUMS-CPS. However there seem to be some discrepancies between the metarea variable and the census file. Abilene, TX for example is 0060 in IPUMS-CPS and 0040 in the “Metropolitan Area and Components” census file from 1990. Several other codes in IPUMS-CPS do not appear to match any codes in the census delineation file. Can you point to the specific census source for the metarea variable in IPUMS-CPS and/or another crosswalk that would allow me to map MSAs to counties? Thank you.

As you have described for Abeline, TX, there is a documentation discrepancy between the METAREA code on the IPUMS CPS site and the 1990 census delineation file. However, the data does not appear to be in error (that is, records coded 0060 do represent Abilene, TX in the data). In other words, we are not following the 1990 MSA codes exactly as the documentation states. IPUMS CPS is actually using the IPUMS USA METAREA codes, which are a modified version of the 1990 MSA codes.

IPUMS CPS will be updating the METAREA documentation to reflect that the codes are modified.

You can also use the IPUMS CPS variable METFIPS, which identifies households to Metropolitan Statistical Areas as they would have been identified when the survey was administered.