Tyler Cowen at Marginal Revolution has a post on age discrimination in academia. "I believe it is very bad, although I do not have data.  I believe that if a 46-year-old, with an excellent vita and newly minted Ph.D in hand, applied for academic economics jobs at the top fifty research universities, the individual would receive very few “bites.” - 

 I'm skeptical. There are plenty of lateral hires of 46-year-olds, with tenure. So why would a department be reluctant to hire a 46-year-old without tenure, who can be fired in 6 years without much problem? And who would have fewer years of life to be deadwood if he burned out? 

   To be sure, it would be odd for anyone to get a Ph.D at age 46, and difficult, given that we of mature years aren't as good at staying up all night doing problem sets or slaving away on the computer to get our professor's numbers ready for his talk the the next day.  And one has to wonder why the person wants to give up 5 or 6 of the most productive years of his life to acquire expertise in a new field in the company of 22-year-olds and start on a career track that is highly risky even for the most talented. But if someone did, and could show a good reason for doing so  (like having made his pile on Wall Street and deciding that he loved economic theory), would he really not get job offers?  I only know of one case. That was a woman whose husband was a big-name professor and whose kids had grown up. She got a PhD in accounting (a  rigorous PhD, with plenty of economics and finance), and got a good job immediately, in the same university as her husband.

    The comments were quite interesting. Most of them were about age discrimination in high-tech. There was strong disagreement as to whether (a) Silicon Valley discriminates in favor of women and minorities or against them, and (b) whether there is massive discrimination against men over 45, or no discrimination against them. A friend here in Boston said that he knows lots of middle-aged dads without jobs because they got too old for their well-paid high-tech jobs.  Why the industry doesn’t want them is a good question. I am told that in prestigious law firms the situation is not as dissimilar as you might think, because many older partners are pressured to retire early by the few who run the firms.