Why would sovereigns ever grant political or economic liberty to their subjects? Under what conditions would rational rulers who posses ultimate authority and who seek to maximize power and wealth ever give up any of that authority? This book draws on a wide array of empirical and theoretical approaches to answer these questions, investigating both why sovereign powers might liberalize and when. The contributors to this volume argue that liberalization or democratization will only occur when those in power calculate that the expected benefits to them will exceed the costs. More specifically rulers take five main concerns into account in their cost-benefit analysis as they decide to reinforce or relax controls: personal power, internal order, external order, and control over policy - particulary economic policy. The book shows that repression is a tempting first option for rulers seeking to maximize their benefits, but that liberalization becomes more attractive as a means of minimizing losses when it becomes increasingly certain that the alternatives are chaos, deposition or even death. Chapters cover topics as diverse as the politics of 17th-century England and 20th-century Chile;