When you marry an economic approach and a freakish curiosity, you frequently find inexpensive and simple  solutions to "unsolvable" problems. The simple explanation is that "people respond to incentives." It`s identifying those incentives and mapping it to the wanted behavior change that gets complicated. If you can look at these behaviors and understand the incentives that lead a school teacher or a sumo wrestler to cheat, you can understand how the subprime-mortgage bubble came to pass. Conventional wisdom uses `consensus building` but that`s often a waste of time and resources. Businesses worry too much about `noisy` risks and not enough about `quiet` ones.

Stephen Dubner, co-author of SuperFreakonomics, discusses the tough questions including global warming and the options of sustainable development versus sustainable retreat and externality. Externality is what happens when someone takes an action and someone else, without agreeing, pays some or all of the costs of that action. An externality is an economic version of taxation without representation. When people aren`t compelled to pay the full cost of their actions, they have little incentive to change their behavior. People respond to incentives. There`s a cumulative advantage to identifying and applying those incentives and thus changing behavior.