A person putting money into a piggy bank (STOCK4B Creative | Getty Images)

You know you should put that $60 away for a rainy day. But your brain keeps telling you, "A Call of Duty: Black Ops 2 in the hand is worth $60-plus-interest in the bush."

Researchers split 91 people into two groups and asked everyone to complete a series of computer-based spending tasks. Here's the twist: One group had access to a single spending account, while the other group had access to the same amount of money spread across multiple accounts. To keep the participants honest, the researchers told everyone to spend wisely because a few would get to keep their accumulated purchases and any leftover cash.


What happened? Those with access to just one account spent about 10 percent less than those with multiple accounts. The researchers tested their findings in three follow-up experiments, and came up with similar results.
Here's why: When all of your money is in one account, you're aware of exactly how much dough you have. If you spend any of it, the dollar total in your head and in your account goes down, says study co-author Himanshu Mishra, Ph.D., an associate professor of marketing at Utah's David Eccles School of Business.


On the other hand, if you have multiple accounts, the total in your head becomes "fuzzy," or inexact, Mishra explains. And when the total in your head isn't a precise figure, it's easier for your brain to justify spending more, he adds. This same phenomenon explains why throwing $50 on a credit card is easier than forking over $50 in cash, the study suggests.
Your takeaway is simple: The fewer accounts you have, the more certain you'll be about your cash total, and the less you'll spend, Mishra says. That is, until the next Call of Duty comes out.