Econtalk is a fantastic podcast about economics, where Russ Roberts chats to the great and the good of the academic world. His politics are libertarian and this jars a little sometimes, when I wish he’d press a guest a little further.
One such instance was his interview with Eugene Fama, famous for his efficient market hypothesis. Essentially, he says that prices reflect all information and so an investor can’t predictably beat the market. This view even predicts that some people will appear to beat the market, through pure chance.
Warren Buffet dealt with this kind of view in a lecture in 1984. In the last 27 years, he’s continued to do pretty well, and is one of the three richest men in the world. If stock picking was pure chance, I don’t see how that explains the continued success of the best (of course it could explain short term good performance). I don’t research finance and I don’t follow all the arguments in this, but it appears bizarre to me.
Perhaps anyone that can see how the market is inefficient is able to make more money exploiting through investing than through writing about it, which means academia will tend to. Michael Lewis’ book certainly seem to show that some people predicted exactly where the system was going to break before it did. It certainly doesn’t seem to be an easy time to argue that financial markets are inefficient.
It is frustrating that whatever evidence is produced Fama just explained it away chance, given the track record of success of investors. He also dismissed behavioural finance with no real explanation (and wasn’t pressed on this by Roberts). I guess nothing is more frustrating than listening to two people agree, when you think they are avoiding evidence.