Good thread, but ignores one of the most — if not the most — important economic cause of this: student loans! Loans cause inflation, because in many cases (including this one), inflation is just a surfeit of money in a certain market.
For the past three decades, student loans have been easier to get and more prevalent than ever in history. Part of that is lower interest rates, part of that is subsidies, and part of that is just a cultural change. However, just a simple economic truism is that an increasing pool of money leads to an inflationary spiral.
And available money will not go unused, even if it doesn’t go to teaching. And that’s exactly what happened — it didn’t go to teaching. Instead, it was devoted to instantiating the administrative apparatuses that are now destroying universities, and those climbing walls, those deluxe gyms, all those amenities that are now de rigeur but were unknown even in the 1980s. It also becomes self-sustaining: as more money is available via student loans, universities add more admins and amenities as they realize they can raise tuition which will be covered by loans. As they then need to pay to maintain these new cost burdens, and to improve it to compete with other colleges, tuition rises again. As tuition rises, universities can then fund more of this useless stuff. But that then requires more and larger loans to pay for this increased tuition. And on and on, ad infinitum.
That’s just basic inflation, and a lot (I’d estimate 70%) of the rise in college costs are due to this loan-created inflationary spiral.