A diner who leaves a 10% tip these days is likely a tightwad, a tourist, or a victim of terrible service, but that same 10% tip would have been perfectly acceptable in the '50s. The going rate for gratuities has steadily crept up over the decades, studies find, hitting 15% by the '70s and '80s and now averaging 18%. The Wall Street Journal looks at the bottom line.
People's desire to be liked by the server is behind the tipflation, says one professor. "If I want the server to really like me, I have to leave an above-average tip," he says, channeling the typical diner. And if diners want not to be disliked, they leave an average tip—a process that drives up the average, but slowly. "I don't think in five years that 25% will be the norm."