During a break at a recent conference on the future of economics, I was carrying the galleys of Jeff Madrick's new book, Age of Greed, when I got into a conversation with Paul Volcker. At 83, the former Fed chairman is a bit hunched but still sharp as an old hawk. Glancing at the book's title, he asked what it was about. "The recent meltdown on Wall Street," I answered, "and how it evolved from deep origins over the past 40 years."

"Ah, that's a good topic," he replied, "though frankly, I've never thought greed defined just one age in American history." The twinkle in his eye made me realize he'd formulated his answer before asking his question--a valuable talent for a central banker.