Michael Greenstone on the importance of strong science in informing policy.
Last week, a divided court of appeals upheld what may well be the most important environmental rule in the nation's history: the Environmental Protection Agency's mercury standards. The regulation is expected to prevent up to 11,000 premature deaths, 4,700 heart attacks and 130,000 asthma attacks a year.
Critics of the mercury rule have focused on its expense. The EPA estimates it will cost $9.6 billion a year, with most of the burden falling on electric utilities. Indeed, the issue of cost is what split the court.
The Clean Air Act allows the EPA to regulate electric utilities under its hazardous air pollutants program only if it finds that such regulation "is appropriate and necessary." Focusing solely on mercury's effect on public health, the EPA made that finding.
That troubled Judge Brett M. Kavanaugh. In his dissenting opinion, he asked, quite reasonably, how the EPA could possibly conclude that regulation is "appropriate" without considering costs. He argued that it's "just common sense and sound government practice" to take account of costs as well as benefits.
But the court's majority had an answer...