During President Trump’s term, the Environmental Protection Agency (EPA) has taken a number of steps to narrow benefit-cost analyses (BCAs), reversing expansive approaches used during the Obama Administration and thereby reducing the calculated benefits of environmental and health regulations. EPA announced what will probably be the last such step on December 4, by adopting a new Part 83 in Title 40 of the Code of Federal Regulations (CFR) entitled “Increasing Consistency and Transparency in Considering Benefits and Costs in Clean Air Act Rulemaking Process.” (I wrote about less formal guidance in a May 2019 memorandum from EPA Administrator Wheeler to his Assistant Administrators HERE.)