Page:Michigan v. EPA.pdf/43

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

21

KAGAN, J., dissenting

text.” 76 Fed. Reg. 24986. And EPA structured its regulatory process accordingly, with consideration of costs coming (multiple times) after the threshold finding. The only way the majority can cast that choice as unreasonable, given the deference this Court owes to such agency decisions, is to blind itself to the broader rulemaking scheme. The same fault inheres in the majority’s secondary argument that EPA engaged in an “interpretive gerrymander[ ]” by considering environmental effects but not costs in making its “appropriate and necessary” finding. Ante, at 8–9. The majority notes—quite rightly—that Congress called for EPA to examine both subjects in a study of mercury emissions from all sources (separate from the study relating to power plants’ emissions alone). See ante, at 8. And the majority states—again, rightly— that Congress’s demand for that study “provides direct evidence that Congress was concerned with [both] environmental effects [and] cost.” Ante, at 9 (internal quotation marks omitted). But nothing follows from that fact, because EPA too was concerned with both. True enough, EPA assessed the two at different times: environmental harms (along with health harms) at the threshold, costs afterward. But that was for the very reasons earlier described: because EPA wanted to treat power plants like other sources and because it thought harms, but not costs, could be accurately measured at that early stage. See supra, at 17–20. Congress’s simple request for a study of mercury emissions in no way conflicts with that choice of when and how to consider both harms and costs. Once more, the majority perceives a conflict only because it takes so partial a view of the regulatory process. And the identical blind spot causes the majority’s sports-car metaphor to run off the road. The majority likens EPA to a hypothetical driver who decides that “it is ‘appropriate’ to buy a Ferrari without thinking about cost, because he plans to think about cost later when deciding