Regulators must rely on science to understand problems and predict the consequences of regulatory actions, but science by itself cannot justify public policy decisions. We review the Environmental Protection Agency's efforts to justify recent changes to its National Ambient Air Quality Standards (NAAQS) for ozone and particulate matter, showing how the agency was able to cloak its policy judgments under the guise of scientific objectivity. By doing so, the EPA evaded accountability for a shifting and incoherent set of policy positions that will have major implications for public health and the economy. For example, even though EPA claimed to base its revised standards on a singular concern for public health, it set the new standards at levels that will still lead to hundreds, if not thousands, of deaths each year. The EPA's claim to rely solely on science contributed to positions that ultimately failed to meet the law’s aspiration of reasoned decision-making by administrative agencies.


Coglianese, Cary, and Gary E. Marchant. "The EPA's Risky Reasoning." KSG Faculty Research Working Paper Series RWP04-046, November 2004.