What's wrong with the U.S. economy?

Growth comes in fits and starts. Unemployment has been over 8 percent for three and a half years. Cutting taxes and interest rates hasn't worked, at least not enough.

To Joseph Stiglitz, the Nobel Prize-winning economist, the economy's strange behavior can be traced to the growing gap between wealthy Americans and everyone else.

In his new book, "The Price of Inequality," he connects surging student loan debt, the real-estate bubble and many of the country's other problems to greater inequality.

When the rich keep getting richer, he says, the costs pile up. For instance, it's easier to climb up from poverty in Britain and Canada than in the U.S.

"People at the bottom are less likely to live up to their potential," he says.

Stiglitz has taught at Yale, Oxford and MIT. He served on President Bill Clinton's council of economic advisers, then left the White House for the World Bank, where he was the chief economist. He's now a professor at Columbia University.