Appreciate the essay and information shared.  A couple of quick thoughts that may be relevant.  First, does the data you reviewed account for investment in facilities?  It could be captured under support costs, but my sense is that colleges have made massive investments in upgraded facilities (many feel like resorts as much as institutions of higher learning) that should be reflected somewhere in the accounting data.  Second, I find the explanation of increased course offerings to be persuasive as a primary driver of the increased costs.  If true, that begs the question of what value is delivered by those extra classes and programs?  Given that our system currently pushes most people towards college and many businesses require 4-year degrees for most of their jobs, we could be looking at a massive squandering of resources on a societal level that has been facilitated by subsidized loans that allow people to absorb cost increases they wouldn't have been able to otherwise - hence distortion of usual market forces that would normally resist the increase.