Is there union information available before 1989?

“Information about union membership was collected in the ASEC CPS beginning in 1983, as part of a series of questions about usual weekly and hourly earnings. The Census Bureau reports that the results in the ASEC CPS public use files for this data series included errors for years prior to 1990, so for the March ASEC supplements only data from 1990 forward are part of IPUMS-CPS.”

Is there any other kind of union information available from IPUMS-CPS that I’m missing prior to 1990? Would the NBER MORGS have this data, or would it include the same errors cited by the census and therefore shouldn’t be used?

Other than the UNION variable for basic monthly samples in 1989, IPUMS-CPS does not currently provide union information prior to 1990. The NBER MORG files do provide union membership data for all samples beginning in 1983. We plan to add this data to IPUMS in the future. In the meantime, I cannot speak to whether or not the NBER union variable is affected by the data errors described in our documentation. I recommend contacting NBER or the Census Bureau directly to confirm the suitability of the MORG data for your purposes.

Hope this helps.