Part of the blame for this falls on the schools, who have every incentive to turn their schools into an ever larger and more prosperous businesses. Part of it falls on the students and their families, who require colleges to provide far more services than used to be the case. Both of these trends are manifested in the way the ratio of non-faculty staff to students at universities is many times higher than it was in the past. Part of it also falls on government agencies like the DOE and similar state agencies for failing to meaningfully rein in college costs. And part of it is probably simple supply and demand, as the gap between earnings for people with degrees and those without has grown, so has the demand for college education and the increase in demand has outpaced a relatively inelastic supply, leading to increased costs.