The Freakanomics podcast covered some of this as well[1]. It was interesting when they covered the racism and sexism aspects.

1: http://freakonomics.com/2013/06/03/should-tipping-be-banned-...

As a restaurateur I love the idea, but shouldn't the service be the same? A good manager isn't waiting for a server to report being undertipped, but actively looking to fill holes that service may have missed.