Credit cards have been extremely profitable to banks. They're profitable not from the fees they collect from the retailers that use the credit cards, that pays the bills, but the real profits come from the interest payments and the charges to users that are unexpected.

One simple step firms can take is make sure that people that are getting paid a lot of money, say more than a million or two, that a big chunk of that money is deferred. That's going to change the whole ballgame.

Recall that people like to do what most people think it is right to do; recall too that people like to do what most people actually do.

A good rule of thumb is to assume that everything matters.

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

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.

There's a second component of a good savings plan, which is something that a colleague of mine called Schlomo Benartzi and I developed many years ago, that we call "save more tomorrow."