When you get to the checkout, you’re probably used to being asked if you want to pay by cash or by card. While electronic payment systems have become increasingly popular in recent decades, cash is still a popular payment method, especially for impulse and extravagant purchases, according to a new United States study.

Researchers Christopher Bechler, Szu-chi Huang, and Joshua Morris have examined consumers’ payment preferences. In their study, recently published in the Journal of the Association for Consumer Research, the researchers note that the use of cash and bank cards differs according to the type of purchase made.

To reach this conclusion, the scientists analysed data from 118,042 actual transactions and subjected over 5,000 participants to six experiments. They found that consumers are more inclined to pay cash when they are unsure of the wisdom of their purchase.

In other words, cash is preferred for extravagant or unreasonable expenses. “When a purchase is difficult to justify – like buying an overpriced bottle of water at the airport, cigarettes or candy – consumers pay with less-trackable methods, like cash, so they can eliminate the paper or electronic trail and ‘forget’ this guilty purchase,” says Bechler.

This preference for cash in the event of more reckless spending is particularly marked among the most rigorous budgeters. It’s an avoidance strategy that allows them to scrutinise their account statements without feeling ashamed or guilty.

Indeed, many individuals are reluctant to look at the state of their finances for fear of being overdrawn. This is the case for some 61% of Americans, according to the National Foundation for Credit Counseling.

For Bechler, it is in the interest of merchants and banking institutions to take into account consumers’ habits regarding different payment methods.

“A doughnut shop could benefit from letting its customers pay with cash because they may want to forget their unhealthy purchase,” he explains. “A salad shop might not see the same benefit.”