"With the assistance of mathematics, I can see a property of the ninety-nine dimensional surfaces hidden from the naked eye. If an increase in the price of fertilizer alone always increases the amount the firm buys of caviar, from that fact alone I can predict the answer to the following experiment which I have never seen performed and upon which I have no observations: an increase in the price of caviar alone will increase the amount the firm buys of fertilizer. In thermodynamics such reciprocity or integrability conditions are known as Maxwell Conditions; in economics they are known as Hotelling conditions in honor of Harold Hotelling’s 1932 work."

“My notion of a fruitful economic science would be that it can help us explain and understand the course of actual economic history. A scholar who seriously addresses commentary on contemporary monthly and yearly events is, in this view, practicing the study of history—history in its most contemporary time phasing.”

“We economists love to quote Keynes’s final lines in his 1936 General Theory—for the reason that they cater so well to our vanity and self-importance. But to admit the truth, madmen in authority can self generate their own frenzies without needing help from either defunct or avant-garde economists. What establishment economists brew up is as often what the Prince and the Public are already wanting to imbibe. We guys don’t stay in the best club by proffering the views of some past academic crank or academic sage.”

“Moral: free markets do not stabilize themselves. Zero regulating is vastly suboptimal to rational regulating. Libertarianism is its own worst enemy!”

“Moral: To understand economics you need to know not only fundamentals but also its nuances. Darwin is in the nuances. When someone preaches “Economics in one lesson,” I advise: Go back for the second lesson.”

“What sex is to the biology classroom, stocks and investment riskiness is to the sophomore economics lecture hall.”

“I would guess that most MIT Ph.D.’s since 1980 might deem themselves not to be “Keynesians.” But they, and modern economists everywhere, do use models like those of Samuelson, Modigliani, Solow, and Tobin. Professor Martin Feldstein, my Harvard neighbor, complained at the 350th Anniversary of Harvard that Keynesians had tried to poison his sophomore mind against saving. Tobin and I on the same panel took this amiss, since both of us since 1955 had been favoring a “neoclassical synthesis,” in which full employment with an austere fiscal budget would add to capital formation in preparation for a coming demographic turnaround.”