To your knowledge, has anyone using the IPUMS-CPS data attempted to allocate income catagories that combine labor and capital income, most notably INCFARM, INCBUS, and INCRETIR, into their capital and labor components?
I’m not aware of anything or anyone specific that has done what you are suggesting here. This might be what you are talking about, but you could roughly categorize the various income components (available on the income variables page) into labor and capital income. For example, INCDIVID and INCRENT are both capital income and INCWAGE is labor income. The rest would be up to your judgement.