Starting in the late 1960s, the Israeli psychologists Amos Tversky and Danny Kahneman began to redefine how the human mind actually works. Michael Lewis's new book The Undoing Project explains how the movement they started -- now known as behavioral economics -- has had such a profound effect on academia, governments, and society at large.

In this busy time of year, we could all use some tips on how to get more done in less time. First, however, a warning: there's a big difference between being busy and being productive.