Here's a new angle on the jobs crisis facing people with Ph.D.'s.

The economics blogger Mike Mandel was curious about the role that various credentials play in the U.S. economy. Sorting through some statistics on college degrees, he was surprised to learn that fully 35 percent of college graduates have a degree beyond the B.A., up from 32.7 percent in 1999. "That seems pretty good, doesn't it?" he writes. "More and more of our college grads are getting advanced degrees, which is exactly what we would want to help foster innovation." The growth is at the masters (and professional) level, however: the proportion of workers with Ph.D's is on a slight downward curve, dipping under 4.5 percent in 2007 and still dropping.

That's doesn't represent an exodus, but perhaps people should flee the Ph.D. path, given another figure Mandel uncovered. While the inflation-adusted earnings of workers with bachelor's or masters degrees have increased very slightly since 1999--a rise of one percent or less--the story was quite different for the doctorate. Employees with Ph.D.'s can expect to earn 10 percent less, in real dollars, than they would have a decade ago. "Yowza," Mandel writes.