Page:Michigan v. EPA.pdf/31

 Cite as: 576 U. S. ____ (2015)

9

KAGAN, J., dissenting

courts: Judges may interfere only if the Agency’s way of ordering its regulatory process is unreasonable—i.e., something Congress would never have allowed. The question here, as in our seminal case directing courts to defer to agency interpretations of their own statutes, arises “not in a sterile textual vacuum, but in the context of implementing policy decisions in a technical and complex arena.” Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U. S. 837, 863 (1984). EPA’s experience and expertise in that arena—and courts’ lack of those attributes—demand that judicial review proceed with caution and care. The majority actually phrases this principle well, though honors it only in the breach: Within wide bounds, it is “up to the Agency to decide. . . how to account for cost.” Ante, at 14. That judges might have made different regulatory choices—might have considered costs in different ways at different times—will not suffice to overturn EPA’s action where Congress, as here, chose not to speak directly to those matters, but to leave them to the Agency to decide. All of that means our decision here properly rests on something the majority thinks irrelevant: an understanding of the full regulatory process relating to power plants and of EPA’s reasons for considering costs only after making its initial “appropriate and necessary” finding. I therefore turn to those issues, to demonstrate the simple point that should resolve these cases: that EPA, in regulating power plants’ emissions of hazardous air pollutants, accounted for costs in a reasonable way. II

A

In the years after its “appropriate and necessary” finding, EPA made good on its promise to account for costs “[a]s a part of developing a regulation.” 65 Fed. Reg. 79830; see supra, at 7. For more than a decade, as EPA