Design can be a powerful tool to manipulate people's choices, maybe even voters. Think of a supermarket. They put the milk in the back, so you have to cruise past all the other merchandise to pick up a gallon. The US Weeklies sit by the register, to capture impulse buyers. It's a subtle but powerful technique known as "choice architecture" - well-known to retailers, and increasingly utilized everywhere from the ballot box to the bathroom to affect - and improve - behavior. University of Chicago law professor Cass Sunstein co-authored a new book on the power of choice architecture called Nudge: Improving Decisions About Health, Wealth and Happiness, and he speaks with Faith Salie on Fair Game.