"The last chapter modeled technological progress as an increase in the number of types of products, N. In this chapter, we allow for improvements in the quality or productivity of each type. This approach has come to be known as the Schumpeterian approach to endogenous growth. We can think of increases in N as basic innovations that amount to dramatically new kinds of goods or methods of production. In contrast, increases in the quality of the existing products involve a continuing series of improvements and refinements of goods and techniques."

“One troublesome aspect is the place of rational expectations macroeconomics in the often political debate over Keynesian economics. At least implicitly, many people feel that what's bad for the rational expectations viewpoint is good for the Keynesian one, and vice versa. But it is hard to see how the problems in using the rational expectations approach to explain monetary nonneutrality can alleviate the theoretical and empirical shortcomings of the Keynesian model.”

“One hypothesis about the delay for the award is that the prize committee realizes that recipients tend to shirk once they get the prize. This consideration was particularly important in Gary’s case because he had continued to exhibit high productivity. Thus, the drop in output caused by an early prize for Gary might have had severe adverse consequences for economic research.”

“Adam Smith is, of course, justly lauded for his advocacy of free markets and limited government. Particularly famous is his idea that each person’s pursuit of self-interest leads, as if by an invisible hand, to socially efficient outcomes.”

“I learned later that economic reasoning was not just mathematics and could be applied to a wide variety of social problems. Now, I think that no forms of social interaction—including religion, love, crime, and fertility choice—are immune from the power of economic reasoning. Hence, even widely held beliefs—for example, that beauty is an illegitimate credential of a worker or that democracy is important for economic growth—are not sacred truths and are subject to analysis.”

“In contrast to Smith’s incomplete modeling, his follower, David Ricardo, provides a coherent setting— basically, the first macroeconomic model—that can be tested, modified, and applied. Although Ricardo is surely narrower and less imaginative and insightful than Smith, he is also a lot better organized. That is why Ricardo’s analysis of macroeconomics—for example, of the implications of public debt—is more coherent and useful than Smith’s.”

“The role of expectations is not limited to monetary policy but is crucial in many areas of economics, as Bob showed in his later research on investment, unemployment, taxation, public debt management, and asset pricing. In all of these situations, the appropriate evaluation of policy takes account of the way that expectations would be rationally formed.”