For universities, you're right. Tuition costs have linearly scaled with both reductions in state taxes devoted to universities and the number and salary of nonfaculty university employees, but the number of faculty or average faculty salaries haven't been strongly correlated with tuition over time. It used to be the case that each college had one dean, and now many have 10, and sometimes up to 30. Not to mention all of their administrative assistants, etc.