From the Victorian poor laws in nineteenth century Britain to the post-war recovery of the 1940s, public works programs have historically played an important role as countercyclical interventions to address seasonal and short-term unemployment. In recent times, the role of public works has broadened, because globalization and economic integration, while expanding opportunities for all, has also increased the exposure to and transmission of risk, especially to the poorest. Public works are now being used increasingly across the developing world as an essential part of the social protection toolkit to respond to risk and persistent poverty. And recent flagship public works programs in Argentina, Ethiopia, India, and elsewhere have sparked even greater interest in their effective use in other developing-country contexts. This book provides a comprehensive overview of public works programs as a safety net instrument and their impacts. It also provides a practical review of program design features and implementation methods, and a compendium of operational and how-to knowledge, combining technical expertise with ongoing country experiences. The book thus fills a major knowledge gap in this field. To date, much attention has been devoted to making the case for improved public works, with less attention paid to the how-to aspects. The target audience of the book includes policy makers and practitioners in national and sub-national governments, donors and international organizations, and nongovernmental organizations, particularly those working in countries where a new wave of social protection interventions has been seen in recent years (e.g., Ethiopia, Ghana, Rwanda) or is likely to emerge in the future (e.g., countries emerging from the Arab Spring in the Middle East, like the Arab Republic of Egypt).