Last week, the Council of Graduate Schools delivered a truly baffling piece of news. From 2011 to 2012, it reported, the number of first-time students enrolled in arts and humanities Ph.D. programs had grown 7.7 percent. Yes, grown. Despite the slow-rolling extinction of the tenured professoriate; despite the fact that academic job openings haven't even come close to recovering from the recession; despite ample doomsaying from publications like The New York Times, it seems students are still signing up at a healthy clip to pause their lives for six years in order to study English, history and the like.

In fact, the enrollment bump was larger in the arts and humanities than almost any other broad field, with the one exception of public administration, as shown on this table from Inside Higher Ed.

All of this leads to me to wonder: Why haven't arts and humanities Ph.D. programs imploded yet? We know, thanks to the collapse of law-school applications, that undergraduate students (as a group, at least) are entirely capable of looking at the job market and making rational decisions about whether or not to pursue a graduate education. Yet in the arts and humanities, in which 43 percent of new Ph.D.'s had no job or postdoc offer by graduation in 2011, there's no real sign of change. From 2007 to 2012, total enrollment fell by a measly 0.4 percent per year,* according to the Council of Graduate Schools. Meanwhile, departments go on merrily producing more new doctorate holders than there are jobs in the academy.