When should we nudge and when should we shove, I think, it's a political judgment. Obviously in some situations we need shoves, we need laws. Fraud is against the law, murder is against the law, drunk-driving is against the law. We don't need just nudges.

It would be much more consumer friendly for them to beep you when you swipe your card that says, uh-oh you're over your limit, are you sure you want to use that?

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.

The reason is they failed to learned the primary lesson we should have learned from when Long Term Capital Management went belly up ten years ago. That is, investments that seem uncorrelated can be correlated simply because we're interested in it.

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.

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."

The assumption that everybody will figure out how much they have to save and then will just implement that plan is obviously preposterous.