Via Ezra Klein:
“John Maynard Keynes famously likened playing the stock market to judging a beauty contest where, rather than choosing the most beautiful girl, you had to choose the girl you thought everyone else would choose as most beautiful. “We devote our intelligences to anticipating what average opinion expects the average opinion to be,” wrote Keynes. This is, with some minor modifications, true for judging the results in Iowa, too.”