There is an interesting and anguishing post on Inside Higher Ed by psychology professor Monica J. Harris entitled Stop Admitting Ph.D. Students. (Hat tip: Chad.) She describes a problem familiar to anybody who's paid attention to the PhD market in probably just about any academic field in the last couple of decades. Departments continue to admit and produce PhD students, and college administrations (and rankings by professional societies) judge departments partly on their ability to produce large numbers of PhD students. Yet, there are very long-term jobs out there for people with PhDs. Knowing that society and her department isn't going to change to address the problem, she's tried to do what she thinks is the only ethical thing she can: she's no longer accepting new graduate students into her lab, so that at least she personally won't be contributing to the oversupply problem.
The comments are also very interesting. The range from agreement and sympathy to outright claims that she is lazy and "not doing her job." I think the best comment was made by "scandal and a byword":
Many of us PhD students DO know what we're getting into. The problem is that (at least in my experience) we're strongly discouraged from making contingency plans. I get a fairly explicit mixed message from my teachers:
1) There aren't many good (tenure-track research) jobs out there.
2) If I don't get a tenure-track research job, I'm a failure, and my name will ever be a scandal and a byword and a source of discomfort to my teachers. If I have any plan B, I'd better not mention it!
My own field is physics, and the problem of physicists being trained for and expected to get tenure-track faculty positions, without enough of these positions being out there, has been a sore topic for two decades (at least). My last year or two of college (1989-1990), I remember reading a national report about how there was going to be a "shortage of scientists". This was based on a rather naive consideration that the boom of scientists who went into the field after Sputnik were all about to retire. In reality, the tech push after Sputnik created a system whereby a tenure-track or tenured physics professor at a research institution produces during his career something like 10-15 PhD students. In other words, while he will retire only once, he replaces himself 10 to 15 times. At first, this worked, because there was demand for that level of expansion. But not for long. Even considering that some will go to smaller, undergraduate-only colleges, this level of over-replacement is not sustainable.
By 1991 or 1992, far from the "shortage of scientists" talks, there were regular columns and letters to the editor in Physics Today talking about how physics graduate students could usually get post-doctoral positions, but it was very tough for those post-docs to move on to a faculty position. At one point, one of Caltech's colloquium periods (perhaps it was Astronomy journal club-- I don't remember exactly) was given over to a discussion of this topic. One of the things parroted there, as in many of these articles, was that we need to be training our PhD students also for jobs outside of academia. Professors said this... but I almost hear each professor present thinking, "but my students will be the ones to get those coveted faculty positions." (Or perhaps it was "but Caltech students will...".)
At least in physics, and at an institution like Caltech, there is a very strong cultural sense that "success" means "ending up in a tenure-track faculty institution at a research University". When, in grad school, I would despair with my friends about our chances, I would sometimes mention that I was as or more interested in teaching than primarily in research, they would say, oh, well, you can get a job at a small liberal arts college! Of course, those jobs are just as competitive as the research jobs. Yes, sometimes people "settle" for those jobs, but the truth is that there are a bunch of us who really value teaching as a primary professional, intellectual, and creative activity.
I also remember hearing students talking about PhDs who had gone on to teach high school, and how depressing that was that they'd have to settle for so little. At the time, I was seriously considering that as a long-term possibility, but I didn't say anything. And this comes back to the comment of "scandal and a byword" above: the culture of PhD granting institutions in many fields remains extremely destructive to the notion of PhDs being self-respecting individuals if they don't get one of the very few coveted faculty jobs.
Many of the comments on thread note that cutting off the opportunity for people to get PhDs cuts off the opportunity for the people who value the PhD work itself. This is a valid point. What I tell people is that if they're going to go to graduate school in physics or astronomy, they should do so because they want to go to graduate school. There is absolutely no guarantee that the PhD will allow them to spend the rest of their lives in physics research. With their skills, the PhD is a more stressful and lower-paying occupation (*) than other things they could be doing. If the coveted faculty job were likely, it might be worth the "sacrifice" of going through a PhD program, but because that faculty job is not likely, the PhD has to be worth it all by itself.
(*) (Aside: in physics, it's a lot better than it is in the humanities. You generally teach for a couple of years, and most of the time your advisor has grant money to pay you a research assistantship to complete your PhD research. In the humanities, you may have a fellowship for a few years, but it's more common to have to teach for many years, or to have to do research assistantships that are not your own thesis research. Yes, you're being paid a pittance in physics, but at least you're being paid.)
You also need to be aware that you're going to receive direct and indirect pressure to consider "success" as going on in research. Even the pep talks about how great a given graduating class is will come across as pressure: "I'm sure you'll go on to do great things to advance the field!" It's supposed to be a compliment, but it bolsters the culture that success is going on in research. You have to be aware of this, and have to be aware that you're still a good person, still a good PhD, and still contributing to society even if you don't manage to go on, or if, horrors, you choose not to go on in research.
The whole culture of the system is broken, and I don't see it changing any time soon. We've been collectively wringing our hands about it for at least a couple of decades, but the evaluation criteria for ranking departments remains "more PhDs" rather than "a responsible number of PhDs", and administrations at Universities continue to pressure departments to produce lots of PhDs to make their numbers look good. How we each respond to this ethically is difficult; I admire Monica Harris' response, and am dismayed by those who think she's finding an excuse to be lazy. Myself, I think the most important thing is to make sure that undergrads going on to PhD programs are not fed a line about a "shortage of scientists", and are fully aware of what they're getting themselves into.