Since Diners Club issued its first charge cards in 1950, payment cards—credit, debit, and charge cards—have revolutionized how and whenwe pay for goods and services. In Paying with Plastic, David Evans and Richard Schmalensee provide a nontechnical distillation of their years of research on the economic, technological, and institutional forces that have shaped the payment card industry. They show how competition works in an industry that does not neatly fit any of the standard economic models. They describe how the payment card companies such as MasterCard and Visa have developed complex systems for coordinating transactions among their thousands of bank members and millions of cardholders and accepting merchants. Evans and Schmalensee also describe recent developments in the industry and consider its likely evolution.