Pork barrel projects would surely rank near the top of most observers’ lists of Congress’s most widely despised products. Yet, political leaders in Congress and the President often trade pork for votes to pass legislation that serves broad national purposes, giving members of Congress pork barrel projects in return for their votes on general interest legislation. It is a practice that succeeds at a cost, but it is a cost that many political leaders are willing to pay in order to enact the broader public policies that they favor. There is an irony in this: pork barrel benefits, the most reviled of Congress’s legislative products, are used by policy coalition leaders to produce the type of policy that is most admired - general interest legislation. This book makes the case that buying votes with pork is one way in which Congress solves its well-known collective action problem.