"As the Internet grows more sophisticated, it is creating new threats to democracy. Social media companies such as Facebook can sort us ever more efficiently into groups of the like-minded, creating echo chambers that amplify our views. It's no accident that on some occasions, people of different political views cannot even understand each other. It's also no surprise that terrorist groups have been able to exploit social media to deadly effect. Welcome to the age of #Republic. In this revealing book, Cass Sunstein, the New York Times bestselling author of Nudge and The World According to Star Wars, shows how today's Internet is driving political fragmentation, polarization, and even extremism--and what can be done about it. Thoroughly rethinking the critical relationship between democracy and the Internet, Sunstein describes how the online world creates "cybercascades," exploits "confirmation bias," and assists "polarization entrepreneurs." And he explains why online fragmentation endangers the shared conversations, experiences, and understandings that are the lifeblood of democracy. In response, Sunstein proposes practical and legal changes to make the Internet friendlier to democratic deliberation. These changes would get us out of our information cocoons by increasing the frequency of unchosen, unplanned encounters and exposing us to people, places, things, and ideas that we would never have picked for our Twitter feed. #Republic need not be an ironic term. As Sunstein shows, it can be a rallying cry for the kind of democracy that citizens of diverse societies most need. "--

Why policies should be based on careful consideration of their costs and benefits rather than on intuition, popular opinion, interest groups, and anecdotes. Opinions on government policies vary widely. Some people feel passionately about the child obesity epidemic and support government regulation of sugary drinks. Others argue that people should be able to eat and drink whatever they like. Some people are alarmed about climate change and favor aggressive government intervention. Others don't feel the need for any sort of climate regulation. In The Cost-Benefit Revolution, Cass Sunstein argues our major disagreements really involve facts, not values. It follows that government policy should not be based on public opinion, intuitions, or pressure from interest groups, but on numbers--meaning careful consideration of costs and benefits. Will a policy save one life, or one thousand lives? Will it impose costs on consumers, and if so, will the costs be high or negligible? Will it hurt workers and small businesses, and, if so, precisely how much? As the Obama administration's "regulatory czar," Sunstein knows his subject in both theory and practice. Drawing on behavioral economics and his well-known emphasis on "nudging," he celebrates the cost-benefit revolution in policy making, tracing its defining moments in the Reagan, Clinton, and Obama administrations (and pondering its uncertain future in the Trump administration). He acknowledges that public officials often lack information about costs and benefits, and outlines state-of-the-art techniques for acquiring that information. Policies should make people's lives better. Quantitative cost-benefit analysis, Sunstein argues, is the best available method for making this happen--even if, in the future, new measures of human well-being, also explored in this book, may be better still.