i too had no idea of such a thing until i attended (as a guest of a columbia econ phd student) an invited talk by susan athey at columbia where she alluded to the exact same consulting rates (though not for this exactly). at the time, it just didn't register because i couldn't connect it to anything i'd ever had experience with (i was an undergrad). that student has now gone on (after graduating) to work in a consulting group that actually does work on M&A type stuff (though she doesn't bill at that rate). and i am now at one of the schools mentioned in your linked article (as a phd student) and this is so well known that it's completely unremarkable.