The raising of the mathematical bar in graduate schools over the past several decades has driven many intelligent men and women (perhaps women especially) to pursue other fields. The graduate training process filters out students who might contribute from a perspective of anthropology, biology, psychology, history, or even intense curiosity about economic issues.
The essay cites Meir Kohn's article on the contrasting economic paradigms.
UPDATE: David Colander discusses graduate education in economics in the latest issue of the Journal of Economic Perspectives. The article does not appear to be available online. One of the findings is that graduate students have no idea what their macroeconomic theory sequence is good for. In that respect, I would say that they understand the sequence better than their professors, who act as if they think it is good for something.
For Discussion. Should the math requirements for obtaining a Ph.D in economics at a top graduate school be reduced? Is it realistic to think that this might happen?