So, what's a nudge? A nudge is some small feature of the environment that attracts our attention and alters our behavior.

Is there a market for somebody selling a credit card that helps people pay down their balances? I think the question is yes. But it would have to be sold by a bank that's really willing to invest in being a trusted partner with its consumers, because they will make less money on each consumer.

Most economists, including me, agree that longevity insurance would make sense for a lot of people.

People worry that if they buy an annuity and then die before the policy starts to pay off, their heirs will lose out. I tell them, "What you should be more worried about is if you outlive your money, you will have to move in with your kids. Ask your kids which of these outcomes they are more worried about."

Rip Van Winkle would be the ideal stock market investor: Rip could invest in the market before his nap and when he woke up 20 years later, he'd be happy. He would have been asleep through all the ups and downs in between. But few investors resemble Mr. Van Winkle. The more often an investor counts his money - or looks at the value of his mutual funds in the newspaper - the lower his risk tolerance.

I'm all for empowerment and education, but the empirical evidence is that it doesn't work. That's why I say make it easy.

People exaggerate their own skills. they are optimistic about their prospects and overconfident about their guesses, including which managers to pick.