Credit cards are a great convenience. They let us buy what we need even when we don’t have enough cash. They make it easy for us to shop online, buy meals, and rent cars when we travel. But credit cards also tempt us to spend more than we can afford.

Studies of consumer behavior show that people spend two to three times as much money when shopping with a credit card as they do when paying with cash. The difference is in the level of impulse shopping. The act of paying with cash reminds us that we have a limited amount of money. We forget that limit— or ignore it—when we pay with a credit card.

When relying on cash, most people are disciplined in their buying and do a good job of ignoring the many impulse temptations they face. Because the cash is hard to part with, they take extra time to find the best bargains. When paying with a credit card, shoppers are much freer with their spending. They pick up those tempting extra items and add them to their carts. They also spend less time comparing prices and looking for bargains.

It goes even further. Credit cards free us to be more generous when shopping for gifts. They make us looser with our money when choosing food and drinks in a restaurant, and when leaving tips. And when we know we’ll be paying with plastic, we rarely buy just the one inexpensive item we were looking for. We add a couple of other things to the cart so we don’t look silly charging a small amount when we get to the front of the checkout line.

Debt isn’t limited to credit card spending. We give credit cards extra attention in this booklet because they offer such an easy way to get into debt. But there are plenty of other opportunities, too. Here are a few:

• Loans from parents and other family members to pay for unexpected (or at least unplanned-for) expenses—a major car repair, a plumbing emergency, winter coats and boots for your kids

• Money borrowed from friends to cover lunch or small expenses

• Gas station cards

• Store account cards

• Paying late, or over time, for services such as dental work and car repairs

• Stretching your budget by paying regular monthly bills late (in effect, borrowing from the companies to which you owe money)

• Payday loans (loans to cover expenses just before payday—generally at very high interest rates)

• Advances on wages or commissions from your employer

• Borrowing from a life insurance policy

• Credit reserve or overdraft privileges on a bank checking account These are all ways to pay for things you need before you have the money to cover the expense. And they’re all ways to accumulate debt.