The authors argue that the fundamental flaw in the Endangered Species Act (ESA) is that it fails to force government decision makers to consider the opportunity cost of their actions, resulting in flawed decision making that imposes heavy costs on landowners without actually protecting endangered species. The authors develop this analysis through an examination of the ESA in light of the modern "living Constitution" theory of interpretation. They conclude that under this theory the ESA's "quartering of species" on private land violates the Third Amendment's ban on quartering soldiers.