As many readers of this blog probably know, the Mercatus Center had a panel in September on why there is no Milton Friedman today. I enjoyed all the presentations. The one I enjoyed most was David Colander's.
Professor Colander's explanation--these are my words, not his--is that it's very hard for there to be another Milton Friedman when the top Ph.D. programs in the country systematically exclude people whose main passion is the economics of public policy. "The profession," says Colander, "does not value the skills that Milton Friedman had." The math filter is so fine that a very large percent of those who really want to do economics don't make it or don't bother. I'm not saying Friedman couldn't have made it. He was, after all, a math major. But if you limit the pool of possible Milton Friedmans to 10 percent or less of the size it would otherwise be, you have less chance of getting an outlier like Milton.