Incentives are everything to an economist seeking to solve workplace problems, and not just financial perks like cash bonuses, says Steven Levitt, Co-Author of "Think Like A Freak". Social incentives are also valuable to improving performance. Levitt and co-author Stephen Dubner offer tips on creative problem-solving in their latest behavioral finance book. Levitt says the rush in behavioral finance books after "Freakonomics" is healthy and good for society. Finally, Levitt gives an example of Freakonomics in action by explaining why Zappos’ policy of paying people to quit increases employee loyalty.