Agricultural research and development has profoundly increased the quantity and quality of food production in the 20th century. As populations increase, however, and land and water resources become more scarce, we must improve productivity and efficiency to provide adequate food supplies. Issues such as the environment, genetic diversity, food safety, poverty, human health, animal rights, public versus private responsibilities, and the question of intellectual property rights further complicate this task. This volume consists of 12 chapters that describe important issues in agricultural science policy, the relevant facts, current economic thinking, and results. Topics include: changing global contexts and agendas for agricultural R&D; productivity measures and measurement; research, productivity, and natural resources; research for genetic improvement; and a conclusion, which suggests directions for the future. The chapters in this volume should provide researchers and policy makers with a timely review of progress on the existing agenda as well as laying the foundation for a new agenda and new directions for global agricultural science policy in the 21st century. Contributors include: Walter J. Armbruster, Peter J. Barry, Wilfred Beckerman, Derek Byerlee, Barbara J. Craig, Robert Evenson, Richard Gray, Zvi Griliches, Paul W. Heisey, Frances Homans, and others.