"One recent history of economic thought (Jürg Niehans’s A History of Economic Theory) devotes twenty-four pages to Samuelson’s ideas. Adam Smith only gets thirteen. Samuelson’s work on stock markets and the random walk takes up less than two of those twenty-four pages. He was “the last generalist in economics,” as he liked to say, and for him financial market studies were just a side project that he at times seemed deeply ambivalent about. His intervention was, however, crucial to the triumph of the random walk. Here was one of the most important economists of all time, and he didn’t think the relationship between coin flips and the stock market was a dinner-speech triviality."