Summary: It's really, really hard to create the right kind of economic incentives -- even if you're a professional economist, and all you're trying to do is teach your kids to use the toilet. On today's Planet Money, we talk to Joshua Gans, an economist at the University of Melbourne -- and his 11-year-old daughter. He explains the system he constructed and rules he enforced. But like tiny Wall-Street bankers, the kids figured out how to work the system for maximum advantage.
