Merging NBER MORG and May files with CPS IPUMS: Help?

I have been reading through the user forum and help files, and am totally stuck on what to do here. Can you give me some guidance on linking NBER outgoing rotation group files and the May files with IPUMS CPS?

The reason I’m trying to do this is because I’m trying to get union coverage at the individual level as far back as I can go, and I know that the May files and outgoing rotation group data on NBER have this information. I have read this:

And this:

And now I’m totally confused. My problems are similar to the person who was having trouble with the MORG data, where a bunch of the supposed ID variables were missing (in some cases from the NBER data, in some cases from both). But then for the May data, I don’t see any of those variables except for line number and household number (no word on #1 or #2). Do you have any idea how to link it right now? And do you have any updates on the project that brings the MORG data back to 1979?

Thank you for your time.

There are three general categories of CPS data files. (a) The basic monthly files, (b) the ASEC files, and © the MORG files. Each of these are available on the NBER site. The blog post you linked to really only supports linking IPUMS CPS data to NBER basic monthly and ASEC data files. As noted in the user forum question you linked to above, supporting the linking of IPUMS CPS data to NBER MORG data files is part of an ongoing project aiming to allow for full comparability and linking of the outgoing rotation groups all the way back to 1979. This project is not yet completed so, unfortunately, there is not much additional information I can provide at the moment.

I hope this explanation is helpful. Please do follow up if there are any remaining questions