School teachers, sumo wrestlers, and life are tied together by one aspect, incentives. Incentives are the driving reason behind doing things, much like motivation. Incentives drive people to get what they want/need, even more so when others want/need the same, which sometimes involving finding loopholes. The author starts with the daycare example. For just a $3 fine, parents could not have the guilt of picking up their child late. The (negative) incentive was not high enough, considering more parents