What are factors leading to rising tuition costs over time? Is there any published work that quantifies the roles of different factors on rising tuition in the U.S. over the past half-century? 

I've heard a number of explanations bandied about, such as:


increases in admin overhead
IT infrastructure costs
Baumol's cost disease
more expensive facilities
reductions in state funding over time (public institutions)


What I'm looking for is some quantitative analysis that tries to estimate how much each of these different factors contributes to the average increases in tuition over time.
The Delta Cost Project, a nonprofit organization in Washington DC, issues reports each year with information about college spending. The highlights of the 2011 report, which I recommend browsing through, states that:


  For the majority of institutions, increases in tuition do not translate into increases in spending. In fact, at most public institutions, tuition increases attempt to compensate for lost revenues from state and local budget reductions, but actual tuition increases are less than half of the actual reduction in state and local appropriations.


Later in the report, other sources of tuition increases are listed, including increases in benefit spending for employees (primarily public institutions). Salary fluctuations are not significant factors; in fact, spending on salaries has gone down slightly over the past few years.

For those interested, I strongly recommend checking out the highlights listed above, as well as the full report, for more details.