Those are standard definitions, and I had to look them up. I hope you don't expect me to defend them; I'm no economist.
It might be I'm just not understanding your objection. I thought that all income was already considered, by the definitions and in data tables like the CBO data Tom linked to below (here). According to the footnotes, those data tables include all income and all taxes, so I have a feeling that somewhere there's somebody who's dealt with your objection.
Not me, I'm afraid. I'm no economist. Thank god, cause that would make me a dismal scientist.