This is because Krugman refuses to take seriously Keynes’s crucial distinction between risk and uncertainty. In my view, Keynes’s major contribution to economic theory was to emphasize the “extreme precariousness of the basis of knowledge on which our estimates of prospective yield have to be made.”
按照凯恩斯的说法，风险和不确定性有着严格的界限。而这也正是克鲁格曼不愿意承认的事情。在我看来，凯恩斯对于经济学最大的贡献在于，强调了“我们所能考虑到的各种极端的偶然情况。”投资者往往有盲点，但最为重要的事情是对未来的预期，从现在的股价推算出未来的上升空间，如果绝大多数人都这么认为的话，他们就是对的。