This week we start with perhaps the most influential American environmental statute ever enacted, the National Environmental Policy Act ("NEPA"), and its requirement for environmental impact analysis of certain actions that might significantly affect the environment. Over 70 countries have enacted programs similar to this one. Then, we study perhaps the strongest American environmental statute ever enacted, the federal Endangered Species Act (“ESA”) and study cases under the ESA that are, among other things, at the cutting edge in the tension between private property and environmental protection. In our theory session, we begin to discuss issues of politics and political economy, and consider a range of topics in the political economy of environmental law.