This problem is in all departs in all subjects across the board, and anyone teaching anywhere in academia should know this. This article is essential for anyone in graduate school to read. Everyone in grad school or with any kind of academic ambition should read this article.
quote from North:
Why does any Ph.D. student at any but the top graduate schools believe that he will get tenure at any university? The odds are so far against him, and have been for a generation, than he ought to realize that he is about to waste his most precious resource – time – on a long-shot. Investing five or more years beyond the B.A. degree, except in a field where industry hires people with advanced degrees, is economic stupidity that boggles the imagination. Yet at least 200,000 graduate students are doing this at any time. Of the 46,000 who earned a Ph.D. in 2003, an equal number (or more) got to ABD status and quit. Probably more than half of the others quit before they got to ABD status.
At $20,000 or more per year in tuition and living expenses, plus the $35,000+ not earned in the job market, trying to earn a Ph.D. is a losing proposition.
In some departments, the years invested are horrendous. Breneman's dissertation went into the grim details, department by department. Anyone seeking a degree in philosophy was almost doomed to failure, yet the Ph.D. degree took on average over a decade beyond the B.A. to earn. There were almost no college teaching jobs when they finished. That was before the glut.
Remember I've said before I am "ABD." Many atheists thought I was lying about something called "ABD" but there it is in North's article.