Since Garrett Hardin published 'The Tragedy of the Commons' in 1968, critics have argued that population growth and capitalism contribute to overuse of natural resources and degradation of the global environment. They propose coercive, state-centric solutions. This book offers an alternative view. Employing insights from new institutional economics, the authors argue that property rights, competitive markets, polycentric political institutions, and social institutions such as trust, patience and individualism enable society to conserve natural resources and mitigate harms to the global environment. The authors support their argument by considering several types of commons: forests, fisheries, minerals, and the global environment. The central lesson of these empirical studies is that following a simple set of rules - definition and enforcement of property rights in response to local conditions, creating and maintaining democracy at the local level, and establishing markets to allocate resources - improves ecological and environmental sustainability. This book will appeal to scholars of natural resources, economics, political science and public policy as well as policymakers who are interested in environmental governance and the ways markets contribute to sustainability.