The more you think about tipping, the less sense it makes.

We tip shoe-shiners, but not shoe salespeople. We tip the delivery men who bring us food, but not those who bring us packages. We tip in French restaurants in the U.S., but not in restaurants in France. Where did this bizarre practice come from? Why does it seem like Americans are the only ones still doing it? And does it even work?

The quick-and-dirty answer to those questions is: Europe invented tipping, Europe abolished tipping, and tipping doesn't really work. As Brian Phillips explained for Slate, there is overwhelming evidence that we tip randomly and mostly out of habit rather than for performance. In the end, the best tip might be $0.00. We should pay service workers a livable wage -- and leave it at that.