According to the British Psychological Society, you might want to skip your morning coffee before heading out to shop. A 2022 study cited by the society found that people who consumed a single espresso before entering a store spent 50% more than those who drank decaffeinated coffee. The researchers explain that caffeine can make people feel more energized, and this heightened energy can lead to more impulsive buying decisions. So, if you’re looking to stick to your budget, it might be best to avoid coffee before a shopping trip.