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

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 lesson from behavioral economics is that people only save if it's automatic.

It turns out, that men, when they're taking care of their business, they're not fully attending to the task at hand, but, I'm sure there's an evolutionary explanation for this, if you give them a target, they will aim.

Maybe you'll take the cash out. So a credit card company or a bank that goes into the business of saying we're going to be the broker, we're going to sell you a mortgage that you're going to be able to pay off, we're going to help you reduce your credit card debt, we're going to help you save for retirement, we're going to put you into mutual funds that have low fees rather than high fees.

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."