This responds in part to a legislative shift of state funds. Retreating from the support of the university's threefold mission of teaching, research, and service, the state transferred dollars from these areas to support instructional costs. The university also shifted resources internally from research and administration to teaching. The relative expenditures at each level of instruction have remained stable. Clearly, the cost of the undergraduate lower level comes from the efficiencies of larger introductory classes, and the higher cost of upper-level instruction reflects both smaller classes and the higher cost of operating laboratories and other specialized teaching environments.
Professional courses are the most expensive.
Many professional programs have restrictions on class size and other requirements placed on them by accreditation criteria that raise the cost of instruction.