MrNerd said:
More PhDs means more tuition income to universities. More income means more research. More research means more discoveries. More discoveries means more prestige. More prestige means more applications. More applications means more PhDs. And so the cycle continues.
Always remember that institutions do things for their own reasons which may or may not be congruent to yours.
Also that's not quite the cycle for physics Ph.D.'s. The other thing is that physics Ph.D.'s don't bring in much in the way of tuition. It's mostly a matter of grant money which ultimately comes from the US federal government.
What happens is this Malthusian system in which one prof produces several Ph.D.'s which become profs. The system very quickly saturates to eat up the available funding. The curious thing is that we hit saturation in 1970, before most of the current crop of Ph.D.'s was born.
One interesting thing is that despite the talk of a massive glut of Ph.D.'s, there really aren't that many. This means that it's easy to lose track of them. One thing that I'd really like to do is to talk to someone that was in the "first lost generation of physics Ph.D.'s" to find out how their life turned out, but it feels a lot like looking for bigfoot.
Why do people churn out more PhDs than necessary?
I don't think that's the question. The question is why can't society make better use of the Ph.D.'s that do get churned out.
As far as what started this. All of this started in the 1950's when the United States was in a life and death struggle with the Soviet Union. The idea was that if the US underproduced physics Ph.D.'s then we'd all be waving red flags and speaking Russian. If the US overproduced physics Ph.D.'s then it might be bad for people looking for jobs, but we'd still have enough people to build toasters and H-bombs.
Also the number of physics Ph.D.'s has been more or less constant since 1965.
A law limiting the number of PhDs, for example would be a bad to someone trying to churn out as many as possible. A stupid and unfair law, but nonetheless, it would at least do something.
It's not hard to limit physics Ph.D.'s, just cut federal funding. The problem is that without Ph.D. students, you'll then have to fire tenured faculty. Also, I think it would be *BAD* *BAD* *BAD* thing for society to reduce the number of physics Ph.D.'s.
One thing that I believe is that society is better off with more educated people, and if we live in a world where that is not true then society is screwed up and we need to change that. The other thing is that even if I never get another chance to study astrophysics full time again, I'll be happy dying knowing that I was able to do it once in my life, and I'd get really annoyed if someone doesn't give me the opportunity to do that.
It's really important to let people going into graduate school know what life looks like at the other end, but if I knew what I know now, I'd still be really interested in getting my Ph.D. I regret nothing about getting my Ph.D. The one big regret that I have is that I felt bad after I got my Ph.D.
But this is useless to me, since I probably won't even be able to get a job at the Patent Office like Einstein managed to do.
Reading Einstein's biography is interesting. One thing that made it possible for him to do what he did was that he had a government 9-5 job, and he had a horrendously turbulent personal life.