"Anytime the EPA wants to issue a new regulation — say, revising how much mercury a power plant is allowed to emit — it looks at both the costs and the benefits before finalizing the rule. The EPA adds up how much companies would likely have to spend on things like installing upgraded scrubbers in smokestacks. Then the agency estimates the economic benefit of imposing the regulation, such as more days with cleaner air or fewer workers calling out sick. The biggest benefits usually come from improving health through things like avoiding hospital visits and reducing early deaths. There is some fuzziness in the numbers on both sides of the ledger though. If a bunch of companies turn to a handful of suppliers for pollution control equipment, that could drive up compliance costs. And how exactly do you price a hypothetical emergency room trip that didn’t happen? “In my experience at EPA, there’s never a perfect estimate of costs or benefits,” McCabe said. Yet even with imperfect calculations, regulators could get a decent sense of whether the juice was worth the squeeze when it comes to a new pollution standard, and the public would get a window into how the decision was made. Under the Biden administration, the EPA found that enforcing the more stringent PM2.5 regulations it issued in 2024 would add up to $46 billion in health benefits by 2032, vastly more than the cost of complying with the rule. The EPA now effectively wants to put receipts from the benefits side of the ledger through the shredder."