This incisive book examines how and why some major policy reforms endure whilst others fail to gain traction and embed themselves. Tracing the development of key policy reforms over time, it offers original insight into how to create and embed positive changes that continue to deliver over the long term. Combining insights from policy studies, policy feedback and government performance, this book focuses on education and environmental reforms in parliamentary democracies. It builds on previous studies of how reforms are designed and passed, advancing academic and policy knowledge on the trajectories of reforms post-implementation. Drawing on detailed case studies from Australia, Canada, Ireland, and Sweden, chapters argue that for reforms to endure, the twin challenges of preservation and adaptation must be recognised and managed. The book shows endurance to be contingent, conditional and contested, progressing non-linearly and dependent on political parties, administrative actors, sectoral interests and mass publics for success. Students and scholars interested in public policy, administration, governance and management will find this book a fascinating read. Using empirical analyses to give novel insight into the workings of government, it will also be an invaluable guide for policymakers and public administrators.