Why do people love their congressional representatives but criticize Congress every chance they get? Although legislatures exist in every political system and are meant to represent the people, they are generally disparaged because they appear both unrepresentative and indecisive. This book explains this puzzling contradiction by examining what representation means, how it can be achieved, and what it takes for a large number of equally representative members to reach decisions. It also describes the methods for studying legislatures that have been developed in the social sciences in the last half century and shows their importance in democratic societies throughout the world.