"I do not mean to say that formal economic analysis is worthless, and that anybody's opinion on economic matters is as good as anyone else's. On the contrary! I am a strong believer in the importance of models, which are to our minds what spear-throwers were to stone age arms: they greatly extend the power and range of our insight. In particular, I have no sympathy for those people who criticize the unrealistic simplifications of model-builders, and imagine that they achieve greater sophistication by avoiding stating their assumptions clearly. The point is to realize that economic models are metaphors, not truth. By all means express your thoughts in models, as pretty as possible . But always remember that you may have gotten the metaphor wrong, and that someone else with a different metaphor may be seeing something that you are missing."

“By 1980, the work of Feldstein, Boskin, Summers, and others had convinced many economists that U.S. taxes were in fact a significant obstacle to investment. Nor was this all: another major U.S. policy, the Social Security system, was also discouraging saving and investment.”

“One interesting footnote: although Friedman made great strides in macroeconomics by applying the concept of individual rationality, he also knew where to stop. In the 1970s, some economists pushed Friedman’s analysis of inflation even further, arguing that there is no usable trade-off between inflation and unemployment even in the short run, because people will anticipate government actions and build that anticipation, as well as past experience, into their price-setting and wage-bargaining. This doctrine, known as “rational expectations,” swept through much of academic economics. But Friedman never went there.”

“...Exxon Mobil is a worse environmental villain than other big oil companies...Exxon, headed by Mr. Raymond, chose a different course of action: it decided to fight the science....And that's just what Exxon Mobil has done: lavish grants have supported a sort of alternative intellectual universe of global warming skeptics....the fact is that whatever small chance there was of action to limit global warming became even smaller because ExxonMobil chose to protect its profits by trashing good science.”

“Milton Friedman was not surprised. In 1968, in one of the decisive intellectual achievements of postwar economics, Friedman not only showed why the apparent tradeoff embodied in the idea of the Phillips curve was wrong; he also predicted the emergence of combined inflation and high unemployment, which Paul Samuelson dubbed "stagflation.”

“Holding people accountable for their past is O.K., but imposing a standard of purity, in which any compromise or misstep makes you the moral equivalent of the bad guys, isn’t. Abraham Lincoln didn’t meet that standard; neither did F.D.R. Nor, for that matter, has Bernie Sanders .”

“The irony, of course, is that high development theory was right. By this I do not mean that the Big Push is really the right story of how development takes place, or even that the issues raised in high development theory are necessarily the key ones for making poor countries rich. What I do mean is that the unconventional themes put forth by the high development theorists their emphasis on strategic complementarity in investment decisions and on the problem of coordination failure — did in fact identify important possibilities that are neglected in competitive equilibrium models. But the high development theorists failed to convince their colleagues of the importance of those possibilities. Worse, they failed even to communicate clearly what they were talking about. And so good ideas, important ideas, were ignored for a generation after they were first enunciated.”