Nudge, by Richard Thaler and Cass Sunstein. incredible book about nudging consumers towards utility-maximising decisions, while largely operating within the sphere of the free market. great for behavioural economics geeks like yours truly.
February 22, 2013 "How high is that ceiling? The President showed Samantha Power and Cass Sunstein's children just how high by throwing a basketball to see if he could touch the ceiling with it." (Official White House Photo by Pete Souza)