The economist article linked here references (and uses in their rankings) data from https://collegescorecard.ed.gov/ https://collegescorecard.ed.gov/, which is

The economist article linked here references (and uses in their rankings) data from https://collegescorecard.ed.gov/ https://collegescorecard.ed.gov/, which is put out by the US Dept of Ed. Looks like there's some additional metrics in there that may be useful.