TThe National Environmental Policy Act (NEPA) is the law that requires Federal agencies to consider the environmental impacts of their actions, involve the public in the decisionmaking process, and disclose information, starting at the initial stages of planning. This fact sheet discusses when you should consider economics in the NEPA process, when to do an analysis, whether or not to use an economist to conduct the analysis, and other statutes, such as the Clean Air Act, you should be aware of.