The Clean Air Act (CAA) serves as one of the main statutes under which the Environmental Protection Agency oversees a broad range of challenges, such as mobile source emissions, air quality, acid rain, and hazardous air pollution.  Better understanding how the CAA can be applied in new contexts is increasingly important given how central this statute has become to the implementation of greenhouse gas control strategies in the United States. This grant provides funds to the American Academy of Arts and Sciences to undertake an in-depth, two-year study looking at the CAA as a model for creating “durable yet flexible” energy and environmental policy.  The first year of the project will involve interdisciplinary research on five different case study applications of the CAA.  The purpose will be to identify and confirm the individual elements that have made the CAA both durable and adaptable since enacted into law nearly 45 years ago.  The second year of the proposed project will then compare these analyses to tease out common “design characteristics” emerging from the case studies.  The research will culminate in a capstone workshop and a companion public event where the results would be widely shared.  In addition, the researchers will produce a set of working papers and articles in peer-reviewed energy and environment journals and make several presentations on their findings to key stakeholders.