What is the role of law in a society in which order is maintained mostly through social norms, trust, and nonlegal sanctions? Eric Posner argues that social norms are sometimes desirable yet sometimes odious, and that the law is critical to enhancing good social norms and undermining bad ones. But he also argues that the proper regulation of social norms is a delicate and complex task, and that current understanding of social norms is inadequate for guiding judges and lawmakers. What is needed, and what this book offers, is a model of the relationship between law and social norms. The model shows that people's concern with establishing cooperative relationships leads them to engage in certain kinds of imitative behavior. The resulting behavioral patterns are called social norms. Posner applies the model to several areas of law that involve the regulation of social norms, including laws governing gift-giving and nonprofit organizations; family law; criminal law; laws governing speech, voting, and discrimination; and contract law. Among the engaging questions posed are: Would the legalization of gay marriage harm traditional married couples? Is it beneficial to shame criminals? Why should the law reward those who make charitable contributions? Would people vote more if non-voters were penalized? The author approaches these questions using the tools of game theory, but his arguments are simply stated and make no technical demands on the reader.

Contract Law and Theory conveys a grasp of theory and policy that makes all of the contract rules easier to understand. By explaining and applying contract theory to a wide range of contracts cases, Eric Posner reveals not only the "what" of doctrine but also the "why"--why one rule rather than another makes sense from a policy perspective. An understanding of what contract theory is and how it is applied will help you to understand not only Contracts, as taught in law school, but also the many areas of law in which contractual ideas operate, such as bankruptcy law, secured transactions, and corporate law. An exciting new Student Treatise from an eminent authority, Contract Law and Theory features: Complete coverage of contracts that includes the principal cases covered in most first-year contracts courses A general explication of the rules of contract that begins with the simplest ideas and gradually builds in complexity A consistent emphasis on the application of theory to doctrine, through analysis of a rich selection of cases A readable and expert treatment of the role of economics in contract law Illustrative examples that point to noteworthy cases Suitable for use alongside any casebook