Emotion, procrastination, and temptation affect spending and saving. People find many ways to waste their money. They pay too much for services they don't use often enough to justify the cost. Gym memberships are one example. New members may pay a big price to sign up for a year or more. They think they will use the gym facilities often, but in reality, they seldom use them.

This makes the price-per-visit very high. It would be less expensive to pay a monthly fee or a pay-per-visit fee which may be as little as $10. Even worse, they fail to cancel their memberships for months after they actually stop going, at a cost of several hundred dollars.

Economists are studying the role of self-control in spending. Self control affects everything from retirement saving to whether or not you use a gift card. Not surprisingly, they discovered that people lack self-discipline.

Before this, it was thought that consumers always do what's in their own best financial interest. Behavioral economists now say that isn't true.

Credit card teaser rates are another example of how people waste money. Zero percent interest sounds good, but when the offer expires, they could be paying 15 percent or more.

They know that the end of the teaser rate is coming or has come a couple of months ago, but they fail to transfer the balance to a lower rate offer. They may pay high interest for months before getting around to transferring the balance.