How does social change happen? When do social movements take off? Sexual harassment was once something that women had to endure; now a movement has risen up against it. White nationalist sentiments, on the other hand, were largely kept out of mainstream discourse; now there is no shortage of media outlets for them. In this book, with the help of behavioral economics, psychology, and other fields, Cass Sunstein casts a bright new light on how change happens.

Unleashed --The law of group polarization -- The expressive function of law -- Nudging : a very short guide -- Forcing choices -- Welfare -- Nudges that fail -- Ethics -- Control -- Coercion -- On preferring A to B, while also preferring B to A -- Transparency -- Precautions -- Moral heuristics -- Rights -- Partyism.