Why drinking coffee can make you spend more money

If you want to spend less on your next shopping trip, try skipping the coffee.

According to a recent study, consumers who drank espresso, tea and other caffeinated drinks immediately before shopping bought more items and often spent more money. Consumers also tended to make more frivolous or fun purchases after they consumed caffeinated drinks.

For instance, in one of the study’s experiments 145 customers visiting a home-goods store in France were given espresso or noncaffeinated drinks before they shopped and were told the drink was a way to welcome them back after the pandemic. The authors found that consumers who drank an espresso spent about $18, while shoppers who had decaffeinated drinks spent roughly half that amount. Customers who drank caffeine also tended to buy more items—1.5 compared with 1.08 for consumers who drank noncaffeinated beverages.

“There have been a lot of studies on the effect of caffeine, but none really looking at how it affects consumer spending,” says Dipayan Biswas, a professor of marketing at the University of South Florida in Tampa, and one of the authors of the study. He says that academic studies show that caffeine tends to make people more energized or excited, and that this heightened state likely causes people to be more impulsive shoppers.

In fact, the shoppers who drank espresso were more likely to make what the studies’ authors describe as “hedonic” purchases—items that were more pleasurable or fun, such as candles, scented oils and artificial plants, in contrast to, say, kitchen utensils or office supplies. Specifically, 74.7% of the items the shoppers bought were classified as “high hedonic,” compared with 40.8% for the noncaffeinated groups.

In a follow-up study, the authors tried to replicate the results in a laboratory setting. This time the study’s subjects were U.S. undergraduates who drank caffeinated or decaffeinated ice tea and then were shown images of Amazon products. The subjects drinking caffeinated tea said they would buy more items—3.83—compared with 3.27 for subjects who had decaffeinated teas. The caffeinated group also were more likely to choose high-hedonic products.