A purely rational economic analysis of human behavior seems unable to explain why some societies tip waiters, busboys or taxi drivers and others don’t. Why are some known for being generous and others for being stingy?
That’s because there isn’t anything rational about it. We tip so that we get better service and food. It’s an incentive. But since we do it after finishing our meal, we lose the ability to incentivize the staff to improve the experience. So why tip if there is no reason it would change your (already consumed) service experience?
But then, whoever said we behave rationally? Well, at least not all the time. So maybe we can explain tipping in some other manner. Is it just a human thing to do, perhaps? That is, more emotional than rational?
An investigation of correlations between typical tipping rates in restaurants across dozens of countries and other metrics suggests exactly that. A key human trait linked to gratuity generosity is whether or not we tend to trust others. Countries that score higher in terms of “interpersonal trust” tend to be better tippers. Those that score lowest, tend to be stingier.
Of course, many factors can come into play in determining when we choose to tip, such as custom, how well paid service-sector employees are and how recognized the services in question are as professions.