I recommend that anyone interested in American HE read Chris Newfield, Ivy and Industry: Business and the Making of the American University, 1880-1980. Here's a follow up quote to yesterday's passage. From page 33:
Since they couldn't turn money into capital, universities focused on controlling costs.... The bulk of any university budget is payroll, and payroll has been a prime target for every kind of financial discipline.
The American university tradition of low faculty salaries goes back 370 years. An equally old tradition has allowed colleges and universities to save money by letting faculty go and herding leftover students into remaining courses.... When salaries rose after World War II and again in the 1960s, largely because of federal infusion of funds into technological fields, payroll costs were contained by expanding the use of non-faculty instructors, especially teaching assistants enrolled in doctoral programs (emphasis added). Since 1980 universities have controlled payroll costs by increasing the use of nontenured and part-time instructors at not quite double the rate of full-time faculty.
The use of GTAs as instructional labor is why we can't act as if "the job market" begins post-PhD; GTAs are already in a "political economy of philosophy instruction" that puts them in competition with TT and NTT folks.