[EliRivers]

I understand that the evidence indicates otherwise.

For example, http://www.marketwatch.com/story/tipping-doesnt-reward-good-... , which suggests that tipping incentivises (amongst other things) touching the customer, telling them they've make good decisions, and (for female service staff) being physically attractive. The customers are like rats in a Skinner box; you just have to do these few simple little things and they hand over extra money. Service staff who make good tips know this, and eventually it teaches contempt for the customers.