Mark Taylor, a professor of religion, has observed (in the New York Times) that
"graduate programs in American universities produce a product for which there is no market (candidates for teaching positions that do not exist)…[with] sometimes well over $100,000 in student loans."This is not really true of the sciences, where the main product is the research that is central to graduate education, research that often leads directly to improvements in healthcare, agriculture, engineering, or environmental quality. Nor do science PhD's usually take on much debt. (If you are applying to grad school in science, and they don't promise you fellowship support or paid teaching opportunities sufficient to meet minimal living expenses, it's either because you are poorly qualified or because the program is poorly funded. Either way, you should reconsider.)
But programs in the sciences do collectively graduate more PhD's than they hire, so a PhD is no guarantee of a faculty position. I have discussed this before.
Taylor's proposed solutions? Several ideas whose effects on the stated problem are hard to predict but probably small (restructuring curriculum, abolishing departments, accepting video games and such as substitutes for traditional written dissertations), one that would make the job shortage worse but might have other benefits (eliminating programs and substituting internet courses), and two that might help new PhD's find jobs (preparing students for nonacademic careers and abolishing tenure). Preparing students for nonacademic careers is something that has been discussed for years and Taylor doesn't offer any new ideas on how to do this. But what about abolishing tenure?
There are two reasons why universities offer tenure, of which Taylor mentions only academic freedom: ensuring that professors can explore important ideas that may be controversial, without fear of losing their jobs. The second reason is that, by offering lifetime employment security, universities can attract top scientists at lower salaries.
It is not generally true, as Taylor claims, that "once tenure has been granted, there is no leverage to encourage a professor to continue to develop professionally." Salary increases depend on success in research and teaching as well as service to the university and society. There may be a few older professors, however, who would rather goof off than work for a salary increase. I don't know anyone like that, but Taylor's experience in a religion department may be different.
How could we discourage people from "retiring in place", without undermining academic freedom? How about letting professors' salaries decrease gradually if their academic performance decreases? (This assumes performance can be evaluated fairly, but we already assume this in awarding pay increases.) Especially if pensions are tied to peak salary, this would discourage professors from hanging on long past their prime.
A potential salary decrease would be much less of a threat to academic freedom than the prospect of having to give up research altogether. ("If I explore the ecological risks of transgenic crops, even though the university gets millions from biotech companies, I could risk a pay cut, but this is more important than money. Besides, if I make some really important discoveries, they might feel compelled to give me a raise, especially if biotech money runs out. Or I could get a better job offer from another university, or a book contract.")
Remember, however, that society supports graduate programs in the sciences mainly because we need the results from the research done by graduate students (apprentices guided by professors), not to provide jobs for professors or PhD's to fill those jobs. Any proposed changes in tenure should consider the impact on research that benefits society as a whole, not just the impact on individuals. Do we want to force everyone to work on what state legislators and university administrators think is most important, or should we allow professors willing to risk pay cuts (or risk forgoing salary increases, under the current system) to explore high-risk ideas with potentially high returns?
By the way, as an adjunct professor, I do not have tenure.