President Donald Trump and newly confirmed EPA administrator Scott Pruitt appear poised to make sweeping environmental policy changes. But strong environmental regulations remain widely popular. Perhaps as a result, the Trump administration may take a subtle approach in attacking environmental rules. Pruitt and other administration officials appear interested in rewriting guidelines for regulatory analysis and they could cook the books so that environmental protections appear to have few or no benefits and exaggerated costs. The results would be sinister, undermining many current and future safeguards for the environment, workplace safety and other important social issues.

These changes matter because long-standing guidelines require the benefits of new regulations to justify their costs. When issuing a rule, a federal agency must prepare a regulatory impact analysis, often hundreds of pages long, spelling out all anticipated positive and negative effects on public welfare and the economy, so that the rule can be objectively evaluated. This process helps ensure that regulations benefit, rather than burden, the economy. There are many ways the Trump administration could inject bias into this analysis, changing the cost-benefit calculus so that existing safeguards could be repealed or weakened, and new rules would be scrapped. If the administration does not protect the integrity of this process, economically rational policymaking and public well-being could be threatened.

With a few changes to a single economic metric, the Trump administration could conceal nearly all the recognized benefits of addressing climate change. A post-election memo from Thomas Pyle, who led the Trump transition team for the Department of Energy, predicted that the Trump administration would end the use of the social cost of carbon, which quantifies the economic damage caused by each ton of carbon dioxide emissions. Compelled by a 2008 federal court ruling, a governmental working group spent years developing this metric, which both federal and state-level policymakers use to objectively evaluate regulations that affect carbon dioxide emissions. This figure is based on rigorous, peer-reviewed science and economics, and it has been vetted by the National Academy of Sciences and other experts. Pyle claimed that the social cost of carbon would be much lower if it were subjected to the latest science, but this claim runs counter a vast body of scientific and economic literature.

If the Trump administration does alter the social cost of carbon, such as by adopting a high discount rate to make future climate damages appear inconsequential, the benefits of addressing climate change could effectively disappear from a cost-benefit ledger. The value of protecting ourselves and our children from dangerous changes in our climate would be artificially set near zero, halting any beneficial protections.

Any effort to limit the use of the social cost of carbon, or finesse its value so it no longer reflects the best available science, would be vulnerable to legal challenges – a federal court recently endorsed the use of the metric. But if successful, such efforts would threaten a wide range of sensible policies that protect the public.

A hostile EPA could also tip the scales against environmental regulation by counting the indirect costs of rules while ignoring indirect benefits. Many EPA rules have significant "co-benefits," as the agency calls them, typically from pollution reductions that are not required by a rule but that will result from the technological or operational changes made to comply with it. Consideration of indirect regulatory effects is consistent with logic, law, scholarship and decades of regulatory precedent. If a rule will protect lives, that is a benefit.

But co-benefits could be one of Pruitt's early targets: he co-authored a brief that attacks the agency's use of co-benefits in a recent lawsuit challenging EPA's mercury pollution standards for power plants. Ordering agencies to stop counting these co-benefits would obscure important public health gains from regulatory actions, undermining many protections. And despite false claims that EPA "double counts" benefits that were already included in past rules' cost-benefit analyses, the agency's analytical guidelines ensure that only new, incremental effects are counted.

The Trump administration could also cease to evaluate the unquantified benefits of regulations, further concealing their value to public well-being (the same brief from Pruitt attacks the use of unquantified benefits). Thanks to peer-reviewed scientific studies, regulators can now evaluate the specific impacts of some pollutants and quantify resulting effects such as hospital costs and missed days of work. For other environmental problems, this research is ongoing, and EPA must do its best to assess effects qualitatively. The agency should not ignore scientific links between mercury exposure and impaired motor skill development when deciding how to regulate. Even if a problem has not yet been monetized, its effects remain real, and regulators should account for these effects however possible.

The administration could also threaten rules by exaggerating their costs, such as by manipulating job impact estimates. The White House website now includes language about "job-killing regulations," and Pruitt's first remarks to EPA employees implied that past agency efforts have slashed jobs. But there is no consistent evidence that environmental regulations contribute to long-term changes in the unemployment rate, and the best predictions by federal agencies estimate that they have very little effect on jobs. However, the models used to estimate job impacts can be easily tweaked to show heavy losses or gains, simply by changing (often undisclosed) assumptions. In one revealing example, the American Coalition for Clean Coal Electricity estimated that two EPA rules on power plant emissions would trigger a 1.4 million job loss; meanwhile, using a different model and different assumptions, the Political Economy Research Institute predicted the same two rules would generate a 1.4 million job gain. EPA estimated the total job impact of the two rules to be relatively small: a combined total of fewer than 50,000 one-time job gains and fewer than 9,000 jobs created annually. But if EPA begins to use misleading job impact estimates like the ones put forward by industry groups, protections for the environment, worker safety and other issues could be scrapped on these grounds.

Regulation is not a cost-free enterprise, and economic analysis can help identify ways to protect the public and the environment in a cost-efficient manner. But there is no room for ideological bias in such an analysis. Efforts to conceal the benefits of safeguards pose a major threat to society, and the Trump administration should avoid these cynical actions.