Implementing the safe minimum standard approach: Two case studies from the US Endangered Species Act

In situations characterized by true uncertainty and potential irreversibility, the safe minimum standard (SMS) approach is a decision rule to protect some critical natural resource-unless the social costs of doing so are somehow ''intolerable.'' The SMS has been discussed widely, but actual case studies remain rare. We present two case studies, focusing on endangered fishes in rite Colorado and Virgin River systems, demonstrating that the legal framework of the U.S. Endangered Species Act (ESA) is consistent with the SMS. The case studies incorporate the results from applied general equilibrium modeling and provide an avenue for investigating excessive economic consequences.