PRESTOPUNDIT

Drezner has an interesting piece on grad school dropouts which references this Chicago Tribune story. Research indicates that most grad students drop out because faculty advisors have little involvement with them. Tenured faculty bring in grad students to teach their classes and do their research -- but commonly their interest in grad students doesn't extend much beyond that. The drop out rate for grad students is 50 percent.

See also this and this. Then, of course, there's this factor:

[Marge, Bart, and Lisa go to their local "Bookaccino" superbookstore.]
LISA: I'm going up to the fourth floor, where the books are!
BART: I'm going to taunt the Ph.Ds!
[Bart approaches the three workers at the espresso bar, all of whom wear glasses and bored expressions.]
BART: Hey guys! I heard a new assistant professorship just opened up!
[Ph.D'd baristas gasp and lean forward eagerly.]
BART: Yes, that's right. At the University of ... PSYCH!

-- The Simpsons.