Debate Erupts Over EPA Cost-Benefits Math: Contextualizing the Relevance of Cost-Benefit Analysis in Clean Air Act Rulemaking

In recent weeks, reactions of outrage have met a policy shift tucked into the Environmental Protection Agency (EPA)’s routine January 15, 2026 final rule amending New Source Performance Standards (NSPS) emissions standards for stationary combustion turbines and stationary gas turbines under a review of stringency that the Clean Air Act requires EPA to undertake every eight years. 91 Fed. Reg. 1,910 (Jan. 15, 2026). In short, EPA explained in the preamble to the rule that its longstanding approach of comparing the costs of controlling emissions to the monetized benefits of avoided health impacts communicated greater certainty than was warranted. EPA said it would stop monetizing such benefits while it considered alternative techniques, though it would still quantify the emissions reductions regulations would achieve.

The criticism has been fierce. “Trump’s E.P.A. Has Put a Value on Human Life: Zero Dollars,” proclaimed The New York Times.¹ A law school professor asserted that “[t]he new, nihilistic E.P.A. position is that environmental safeguards have essentially no benefits.”² The move was called a “dangerous abdication,”³ “morally wrong,”⁴ and “repulsive.”⁵ The Harvard School of Public Health warned of serious health consequences.⁶

Readers might wonder, is EPA now saying no costs for controlling air emissions can be justified? Is EPA really prepared to throw out all Clean Air Act standards because no costs or burdens are worthwhile? In short, the answer is no. Just as the current administration maintains that prior EPA rules may have exaggerated to the public the monetary benefits of its emissions regulations, the current criticism is more political than rooted in the specific law governing air pollution regulation. The administration’s change is no doubt consequential in how EPA broadly shapes its policy priorities and objectives — and potentially ripe for scrutiny from experts in the evaluation and comparison of the costs and benefits of regulations — but it should not be confused with a rewriting of the Clean Air Act requirements for agency decision-making.

EPA’s policy shift relates to a technocratic practice of analyzing costs and benefits of all federal regulations with major impacts on the U.S. economy established by executive orders dating to the Carter and Reagan administrations, under the direction of the Office of Management and Budget (OMB). Those analyses stand quite apart from EPA’s primary job of adopting air emissions regulations according to factors established by Congress in the text of the Clean Air Act. The Clean Air Act that Congress enacted in 1970, and comprehensively revised in 1977 and 1990, directs EPA to establish air pollution regulations without weighing industry costs against public monetized health benefits. An inherently political body, Congress perhaps understood that our society recoils from putting a price on health and life, especially in prospective regulation.

We do not like the notion that — at a certain point — it costs too much for industry to bear additional costs to avoid causing people illness or death. Indeed, headlines mirroring those elicited by the Trump administration have greeted prior attempts to put a number on the value of a human life: “What’s a Life Worth? Under the Reagan Administration, It May Be Less Than You Thought,” announced The Washington Post in 1985 when that administration’s demands threatened workplace safety regulations.⁷ Understanding that monetizing human health and life in this way is politically vexing and potentially disabling, Congress largely chose to avoid it. Public health studies have concluded that the Clean Air Act has achieved unparalleled public health benefits and has imposed high costs to achieve those benefits, all without requiring the kind of comparison of costs to monetized health benefits that the commentators suggest is so important. As such, EPA’s Clean Air Act regulations have been the most litigated in the courts of appeals and Supreme Court of any environmental statute, in which cases the courts have at times emphasized the importance of cost considerations but repeatedly affirmed Congress’s directives to draw lines without weighing costs and public health benefits. After a half-century of public health achievements, the more important question is how to move forward. As large gains have been achieved and incremental improvements come at increasing costs, and EPA grapples with reliance on the Clean Air Act to tackle climate change, the place of cost-benefit analysis in air pollution regulation warrants more transparent consideration and debate.

What Did EPA Do in the Turbines NSPS Final Rule?

New Source Performance Standards are basic federal emissions standards that EPA sets under Section 111 of the Clean Air Act for sources of air pollution. Under Section 111(b), EPA establishes a list of categories and subcategories of sources that, in the EPA Administrator’s judgment, “cause[], or contribute[] significantly to, air pollution which may reasonably be anticipated to endanger public health or welfare.” In listing the categories and subcategories and the relevant pollutants, EPA is not weighing costs of emissions controls against benefits. The question is simply whether the emissions pose a danger to public health or welfare. Once EPA establishes the list, it then must set a federal “standard of performance” for new sources under Section 111(b), and may also set standards for existing sources under Section 111(d) that states are to implement. Key here is the definition of “standard of performance” to mean a standard that “reflects the degree of emission limitation achievable through the application of the best system of emission reduction which (taking into account the cost of achieving such reduction and any nonair quality health and environmental impact and energy requirements) has been adequately demonstrated.”

Critically, the analysis is technology-based, not health-based. The best system of emission reduction (BSER) involves comparing available technologies to determine which is “best,” and then deriving from that technology an “achievable” emissions limit. It does not involve weighing the costs of achieving the air emissions limit against the public health benefits of reducing the air pollution. (Non-air quality health and environmental impacts are a consideration in weighing technologies against each other.) Recognizing that technology advances over time, Congress directed in Section 111(b) that EPA revisit the NSPS every eight years.

The U.S. Court of Appeals for the District of Columbia Circuit held soon after enactment of the Clean Air Act in Portland Cement Ass’n v. Ruckelshaus, 486 F.2d 375, 387 (D.C. Cir. 1973), that the consideration of “cost” does not require EPA to prepare “a quantified cost-benefit analysis, showing the benefit to ambient air conditions as measured against the cost of the pollution devices.” This interpretation was authored by Judge Harold Leventhal — a titan of administrative law — who recognized that imposing such a requirement would hamstring the agency. Noting that such a strict requirement would conflict with the “time constraints” imposed by Congress for EPA’s first NSPS, Judge Leventhal also identified “[t]he difficulty, if not impossibility, of quantifying the benefit to ambient air conditions.” Id. Overall, the Washington, D.C. Circuit has read Section 111 as giving “EPA broad discretion to weigh different factors in setting the standard” for stationary sources. Sierra Club v. Costle, 657 F.2d 298, 321 (D.C. Cir. 1981).

Consistent with this precedent, when EPA published its proposed amendment to the NSPS for turbines under the Biden administration, the agency made clear that its evaluation of costs was “not intended to constitute or approximate a benefit-cost analysis in which monetized benefits are compared to costs.” 89 Fed. Reg. 101306, 101312 (Dec. 13, 2024). Rather, EPA considered the reasonableness of costs associated with pollution controls and their “cost effectiveness” by comparing “relative costs and outcomes (effects) of two or more options.” Id.

In the January 15 final rule, EPA amended the NSPS for stationary combustion and gas turbines pursuant to an eight-year review. EPA considered various technologies available to control nitrogen oxide (NOx) and sulfur dioxide (SO2), and established new subcategories for stationary combustion turbines, created a new subcategory for such turbines used in temporary applications, and addressed emissions limits according to the statutory directives. As in the proposal, EPA did not base any change in emissions limits on a weighing of costs against health benefits, or by assigning a zero value to health benefits in any such comparison. That would have been unlawful and would have opened EPA to obvious legal challenges to the validity of the rule in court. EPA did project emissions benefits from the final rule, estimating in a table the net annual tons of NOx emissions changes, estimating a range of 15 to 296 tons of reductions in 2032. 91 Fed. Reg. at 1,962, Table 2.

Why Then Was EPA Addressing the Weighing of Costs Against Public Health Benefits?

Following the Nixon administration’s establishment of the modern Office of Management and Budget (OMB) almost contemporaneously with enactment of the Clean Air Act in 1970, President Carter first mandated through Executive Order 12,044 that OMB oversee analysis of compliance costs of “major rules” promulgated by federal agencies. But it was the Reagan administration that supercharged OMB oversight of agency rulemakings and established a centralized system of review predicated on cost-benefit analysis of major rules. President Reagan issued Executive Order 12,291 soon after taking office, which required agencies to prepare a Regulatory Impact Analysis (RIA) for every “major rule” (those with an “annual effect on the economy of $100 million or more”) that described costs; benefits, “including any beneficial effects that cannot be quantified in monetary terms”; and the net benefits of the rule, “including an evaluation of effects that cannot be quantified in monetary terms.” Exec. Order 12,291, 46 Fed. Reg. 13193, § 3 (Feb. 17, 1981). Executive Order 12,291 stated plainly that “[r]egulatory action shall not be undertaken unless the potential benefits to society for the regulation outweigh the potential costs to society,” and barred agencies from publishing proposed or final major rules until OMB finished its review. Id.§§ 2(b), 3(f)(1). It further empowered OMB to determine whether a proposed action constituted a “major rule” and to send the rule back to agencies to perform additional analysis. Id. §§ 6(a)(1), (3).

Beginning with Executive Order 12,291, a debate has raged over the imposition of cost-benefit analysis on agency regulations — particularly those implementing environmental, health, and safety measures. President Reagan’s OMB was criticized for lacking transparency and was viewed as imposing a deregulatory agenda by delaying agency rulemakings and emphasizing costs to industry over benefits to the public. Some advocates for regulation argued that the monetization of health and environmental benefits was inimical to those interests and fundamentally incapable of capturing their true worth.

Nonetheless, cost-benefit analysis became a bipartisan proposition in 1993 when President Clinton issued Executive Order 12,866, which preserved President Reagan’s centralized system of review within OMB’s Office of Information and Regulatory Affairs (OIRA) while imposing some reforms like disclosure requirements and deadlines for review. Exec. Order 12,866, 58 Fed. Reg. 51, 735, § 6(b) (Sep. 30, 1993). President Clinton also took steps to ameliorate anti-regulatory bias in the cost-benefit comparison by providing that it include “both quantifiable measures . . . and qualitative measures of costs and benefits that are difficult to quantify, but nevertheless essential to consider,” including consideration of “distributive impacts” and “equity.” President Obama likewise preserved the OMB review process and supported the use of cost-benefit analysis. See Exec. Order 13,563, 76 Fed. Reg. 3821 (Jan. 18, 2011). Notwithstanding political divisions over cost-benefit analysis, notable progressive advocates have argued that, when properly applied, the framework can be a neutral tool that effectively allocates scarce resources and increases transparency in government decision-making.⁸ And in recent years, traditional political divisions over the use of cost-benefit analysis have shifted, with progressives highlighting enormous estimated benefits of clean air regulations and conservatives questioning math that supports a pro-regulatory agenda.⁹

The RIA process has not been limited to the Clean Air Act or public health regulation. And it is solely an Executive Branch initiative; it is not legislative and is not judicially enforceable. If an agency fails to prepare an RIA for a regulation as specified in the executive orders, the agency is answerable to the President and the regulation may get delayed. It is not a legal defect that courts will enforce, and it does not authorize agencies to avoid otherwise mandatory statutory obligations. See Exec. Order 12,866 § 10 (“This Executive order is intended only to improve the internal management of the Federal Government and does not create any right or benefit, substantive or procedural, enforceable at law or equity by a party against the United States, its agencies or instrumentalities, its officers or employees, or any other person.”).

Nevertheless, agencies, including EPA, have dutifully prepared RIAs and in so doing have developed cost-benefit analytic techniques over the last fifty years to monetize public health benefits of regulations in order to weigh them against costs on a common metric of dollars. EPA’s policy shift in the turbines final rule was focused on this RIA analysis mandated by Executive Order 12,866, and not part of the legal justification for the standards EPA reviewed and amended. In performing this analysis, EPA quantified the number of turbines it projected would be affected, the tons of NOx emissions that would be reduced from 2025 to 2032, a projected increase in ammonia emissions (due to technology used to control NOx emissions), and a resulting increase in fine particulate matter. EPA also qualitatively described the health impacts of the air pollutants. EPA also explained the projected costs of the emissions controls and cost savings for more efficient turbines in a high-efficiency subcategory, as well as expected small market impacts. Where EPA deviated from past practice is that the agency declined to monetize the public health benefits of NOx and fine particulate matter reductions. In particular, EPA explained that the practice of monetizing benefits of avoided health impacts achieved through reductions in air pollution has given the public a false sense of precision beyond what the underlying science can fully support. As a result, EPA announced that it is no longer monetizing fine particulate and ozone pollution benefits and will consider various techniques to characterize uncertainties in such estimates, and will seek peer review for any such new methods consistent with OMB guidance.

EPA’s current retreat from monetizing public health benefits may well be debated by technocrats with expertise in assigning dollar values to mortality and morbidity, encompassing lost life years, hospital admissions and health care system expenditures, loss of worker productivity, asthma attacks, and the like. Whether such comparisons on a common dollar metric marshal public support for or resistance to EPA regulation may also be debated. How much does it matter whether EPA explains in its final rules that regulations to reduce air pollution cost X dollars compared to Y avoided deaths, as opposed to quantifying the value of those avoided deaths in dollars? What is not debatable is that such a dollar comparison is not the basis Congress established for EPA lawfully to consider in setting NSPS emissions limits or essentially all other Clean Air Act programs.

How Did Congress Direct EPA to Regulate in Other Clean Air Act Programs without Cost-Benefit Analysis?

At the core of the Clean Air Act, dating from 1970, are the National Ambient Air Quality Standards that establish health-based ambient limits for major air pollutants that many other requirements are then designed to achieve across the country by controlling emissions from various sources. The ambient standards themselves, however, are set irrespective of weighing costs against benefits. Section 108(a) requires EPA to identify air pollutants that are emitted by “numerous or diverse” sources and whose presence in the atmosphere “may reasonably be anticipated to endanger public health or welfare.” The agency must then publish air quality “criteria” for each listed pollutant that will “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of such pollutant in the ambient air.”

Using these criteria, Section 109(b) instructs EPA to establish ambient concentrations for those pollutants, “the attainment and maintenance of which … are requisite to protect the public health” with “an adequate margin of safety.” EPA has set such “primary” national ambient air quality standards(NAAQS) for six “criteria air pollutants”: ozone, particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead. (“Secondary” NAAQS may also be established, aimed at non-health environmental impacts.) Title I of the Clean Air Act is organized around achieving these NAAQS, with states primarily responsible for designating areas within the state as attaining or not attaining the NAAQS, and adopting State Implementation Plans to attain and thereafter maintain them. The statute includes a variety of direct federal and mandatory state programs, of which the NSPS under Section 111 is just one component, aimed at supporting states in achieving the NAAQS. Further, the NAAQS are not static, but rather Section 109(d) directs EPA to consider new scientific information and reconsider the NAAQS every five years.

Given the significance of the NAAQS in driving emissions reductions, with associated large costs to industry and public health benefits at stake, EPA’s setting and subsequent ratcheting down of the NAAQS over the last half century has been hotly contested in EPA rulemaking and litigation challenging NAAQS revisions. In 2001, the Supreme Court definitively resolved in Whitman v. American Trucking Association, 531 U.S. 457 (2001), that the Clean Air Act’s “adequate margin of safety” statutory directive prohibits EPA’s consideration of costs when setting NAAQS. By statute, NAAQS are based on the “maximum airborne concentration of a pollutant that the public health can tolerate,” id. at 465, not a comparison of costs and monetized health benefits. The NAAQS provision requires EPA to set a standard that protects public health, regardless of any monetary or other valuation the agency might place on public health.

Since the central premise of the NAAQS is that they must be set to drive down ambient air pollution to levels that are deemed safe without considering costs, other statutory programs aimed at achieving those standards likewise do not allow for weighing costs against public health benefits. After all, where Congress has directed EPA to ensure that the NAAQS are achieved, it would not make sense to impose costs that outweigh the public health benefits as a hurdle that must be cleared to impose emissions limits on particular types of sources. The costs of control options can be weighed against each other or in determining the feasibility of a particular control option, but weighing the costs against public health benefits is not relevant.

Thus, like the NSPS, the statutory program in Title II of the Clean Air Act directing EPA to establish nationwide emissions standards for air pollutants from new cars, trucks, and off-road engines is fundamentally based on technological feasibility, rather than a comparison of costs and public health benefits. Section 202 does require EPA to consider the costs to industry in developing and applying the technology needed to reach a standard, and allow commensurate lead time. This cost comparison is between potential technologies, not between costs of compliance and public health benefits. See NRDC v. EPA, 655 F.2d 318 (D.C. Cir. 1981) (discussing costs of diesel particulate emissions control technology).

Indeed, even outside of the NAAQS and supporting regulations to reduce “criteria” air pollutants, other Clean Air Act programs also steer clear of cost-benefit analysis as a basis for EPA standard-setting. One such program is Section 112 regulation of the many types of carcinogenic, mutagenic, and other hazardous air pollutants (HAPs), as distinct from the six criteria air pollutants. Under the 1970 statute, Section 112(a)(1) defined HAPs broadly to mean pollutants “anticipated to result in an increase in mortality or an increase in serious irreversible, or incapacitating reversible, illness.” For such pollutants, the original statute specified a similar approach as applies for the NAAQS: the statute directed EPA to set emissions standards for sources of HAPs to “provide[] an ample margin of safety to protect the public health[.].” The number and diversity of HAPs and sources of HAP emissions made this unwieldy for EPA. Too many chemicals met the statutory definition, analysis of emissions and risks for all of them was overwhelming, and many were so potent that the only acceptable standard to ensure an “ample margin of safety” seemed to be zero. As a result, EPA made little progress, promulgating only eight HAP standards by 1990.¹⁰

Even then, Congress’s course correction in the 1990 amendments did not adopt cost-benefit analysis, which would have pit industry costs against monetized health benefits of reductions in serious illnesses such as cancer and birth defects. Instead, Congress listed 186 HAPs by statute, provided for additions to the list, and directed EPA to adopt standards in the first instance based on available technology to control emissions from various source categories, more similar to the NSPS and motor vehicles and engines standards. The 1990 amendments overhauled Section 112, removed the definition of hazardous air pollutant, introduced a list of HAPs, and instructed EPA to set standards at the “maximum degree … achievable[.]” More specifically, the amended Section 112(d) directs EPA emissions standards for the listed HAPs that must be as stringent as the best controlled similar source in each industry category. Selecting a “maximum achievable control technology” (MACT) does require the agency to compare costs — but only among available technologies, and not against monetized health benefits.

Section 112 partially retained the “ample margin of safety” approach for HAPs that is similar to the “adequate margin” for NAAQS, but only in a follow-up requirement to address residual risk following the setting of technology-based standards. EPA has, in recent years, issued a few more stringent NESHAPs based on an ample margin of safety following residual risk review, but overall, the HAPs program remains predominantly driven by technology standards.¹¹

The phaseout of ozone-depleting substances (ODS) under Title VI of Clean Air Act is another example of a program that proceeds without cost-benefit analysis. That title required EPA to phase out chemicals — refrigerants and blowing agents — that were destroying the stratospheric ozone layer, consistent with U.S. obligations under the Montreal Protocol. This was a simple phase-out mandate, where alternative refrigerants had been developed. Under Section 606(a), EPA was empowered to accelerate the statutory phase-out schedules where scientific evidence indicates a need for faster action, technological advances make acceleration feasible, or the Montreal Protocol is modified to require faster phase-out. But the phaseout was mandatory; EPA had no power to slow the schedule in the face of high costs, or to make concessions that balance the phaseout's costs with public health benefits. Section 612 established the Significant New Alternatives Program (SNAP), which requires EPA to evaluate substitutes for ozone-depleting chemicals. Of note, Section 612(c) required EPA to promulgate rules making it unlawful to replace such ozone-depleting chemicals with a substitute that EPA determines “may present adverse effects to human health or the environment, where the Administrator has identified an alternative to such replacement that (1) reduces the overall risk to human health and the environment; and (2) is currently or potentially available.” Hence, even when expressly considering human health impacts, Congress’s directive was to compare alternatives, not to weigh costs against monetized health benefits.

Does the Clean Air Act Require Consideration of Monetized Health Benefits Anywhere?

The most focused attention on comparison of costs and monetized health benefits in Clean Air Act regulation and litigation since Judge Leventhal’s Portland Cement opinion in 1973 came in the Supreme Court case of Michigan v. EPA, 576 U.S. 743 (2015), concerning EPA regulation of hazardous air pollutants, and particularly mercury, from power plants. Given extensive other programs aimed at power plants, including the then-new acid rain program targeting sulfur dioxide emissions in the 1990 Amendments, Congress carved out a special provision to address HAPs from these plants in Section 112(n). There, Congress directed that several studies be undertaken, and then that EPA consider the results and “shall” regulate HAPs from power plants if it finds that “regulation is appropriate and necessary.” EPA determined to regulate without comparing costs and benefits, concluding that regulation was “appropriate” because mercury and other HAPs from power plants posed risks to human health and the environment, and controls were available to reduce the emissions; and regulation was “necessary” because the other regulation of power plants did not eliminate the risks. 77 Fed. Reg. 9330, 9363 (Feb. 16, 2012). Separately, in the regulatory impact analysis required by executive order, EPA calculated a cost of nearly $10 billion per year, public health benefits from HAP reductions of $4–6 million per year, and “co-benefits” of reducing particulate emissions at $37–90 billion per year. Id. at 9,306.

The Supreme Court invalidated EPA’s decision, holding that the “appropriate and necessary” test encompasses all relevant factors, and EPA, therefore, was required to consider costs among those factors. Justice Scalia’s opinion makes the case for the technocratic logic underlying the Reagan and subsequent executive orders. The opinion emphasized not only the breadth of the “appropriate and necessary” language but also basic administrative law requirements to engage in “reasoned decisionmaking,” to follow a “logical and rational” process, and to act “on a consideration of the relevant factors,” 576 U.S. at 750 (citations omitted). Observing that “EPA refused to consider whether the costs of its decision outweighed the benefits,” id., Justice Scalia reasoned that “[o]ne would not say that it is even rational, never mind ‘appropriate,’ to impose billions of dollars in economic costs in return for a few dollars in health or environmental benefits” and “[n]o regulation is ‘appropriate’ if it does significantly more harm than good.” Id. at 752. Stating the case for cost-benefit analysis, the opinion elaborates: “[R]easonable regulation ordinarily requires paying attention to the advantages and the disadvantages of agency decisions” and “reflects the reality that ‘too much wasteful expenditure devoted to one problem may well mean considerably fewer resources available to deal effectively with other (perhaps more serious) problems.’” Id. at 752–53 (emphasis in original and citation omitted).

Even with this full-throated case for cost-benefit analysis, Justice Scalia’s opinion nevertheless stopped short of contradicting Judge Leventhal by requiring a comparison of costs and monetized health benefits. Asserting that “[t]he Agency must consider cost” before deciding whether regulation is “appropriate and necessary,” the opinion continued: “We need not and do not hold that the law unambiguously required the Agency, when making this preliminary estimate, to conduct a formal cost-benefit analysis in which each advantage and disadvantage is assigned a monetary value. It will be up to the Agency to decide (as always, within the limits of reasonable interpretation) how to account for cost.” Id. at 759.

On remand, EPA proceeded to support its finding that HAP regulation of power plants was “appropriate and necessary” by taking into account a favorable comparison of monetized benefits at $37–90 billion (including the co-benefits of particulate reductions) against $10 billion in costs. 81 Fed. Reg. 24420 (April 25, 2016).

To be sure, some eager readers of Justice Scalia’s Michigan opinion have interpreted it to require some form of cost-benefit analysis — minimally, consideration of “the advantages and the disadvantages” — for any agency’s rulemakings to pass muster.¹² And some jurists have sought to apply Michigan that way.¹³ Similarly, reactions to the Trump administration’s recent announcement have emphasized Michigan and argued for the irrationality of EPA’s sudden reversal and lopsided approach. A court may end up scrutinizing EPA’s decision and reasoning under the Administrative Procedure Act’s “arbitrary and capricious” standard, but the statutory language, structure and extensive case law make it highly unlikely that a court will conclude that monetized costs and benefits must be considered under Section 111.

So, What Has the Clean Air Act Achieved Without Cost-Benefit Analysis?

Largely sidestepping the fraught comparison of costs against monetized health benefits, the Clean Air Act has been remarkably successful at reducing air pollution. EPA’s website touts various achievements under the Act.¹⁴ According to the agency, between 1970 and 2020 combined emissions of common pollutants dropped by 78%. From the 1990 amendments to 2020, carbon monoxide fell 73%, nitrogen dioxide fell by 61%, ozone fell by 25%, sulfur dioxide fell by 91%, fine particles fell by 41% (from 2000), and lead fell by 86% (from 2010). Stationary sources now emit 1.5 million fewer tons of air pollutants per year than they did in 1990. Basically, all current-year on-road vehicles are 99% cleaner than 1970 models; several motor vehicle standards have tightened by over 90% since they were first enacted. This tremendous relief from high pre-1970 air pollution¹⁵ accompanied a near-tripling of U.S. GDP.¹⁶

Indeed, a 2019 review of economic literature found — despite the complexities of measuring the direct and indirect costs and benefits of the Act — “a general consensus that the benefits of clean air legislation over the past fifty years are likely to have greatly exceeded the costs.”¹⁷ Generally, economists have found that early compliance-cost forecasts often overshoot, and benefits sometimes cannot be fully evaluated until a program takes hold. Under the acid rain program, for example, electricity-generating units found cheaper compliance than anticipated by purchasing low-sulfur coal. And while the program’s primary anticipated benefit was ecological (to curb the acidification of lakes in the Northeast), ultimately over ninety-five percent of the program’s benefits were associated with human health benefits from reduced particulate matter. Such benefits might not necessarily appear in ex ante analysis, such as an RIA. Overall, EPA’s technocratic comparisons in RIA analyses showing costs lower than monetized health benefits may provide political support for more stringent regulation. Likewise, EPA might prefer to avoid quantified comparisons of costs and monetized health benefits for regulatory rollbacks than those showing lost health benefits exceeding cost savings.

Conclusions

From air pollution and other environmental protection to safety regulations to tort law, unease with putting a price on health and life is not new in the law. From Judge Leventhal’s 1973 observation of the challenges of quantifying the benefits of ambient air quality standards to Justice Scalia’s 2015 insistence that weighing costs against benefits is fundamental to rational decision-making, there is an inherent tension between our expectation that government’s job is to protect us against harm caused by others and a technocratic recognition that the costs of preventing all such harm might be too high. Notwithstanding the clamor over EPA’s suspension of monetizing health benefits in its recent Clean Air Act rulemaking, Congress has directed EPA to set air pollution standards under that statute without comparing costs to monetized health benefits. Instead, the statute functions by directing EPA to set ambient standards that are safe without regard to cost, and then to set requirements for sources of pollution by comparing costs and feasibility of various technologies to achieve the standards most cost-effectively without revisiting the ambient goal. By all accounts, the statute has been spectacularly successful in protecting public health at an acceptable cost to society. To be sure, starting from a blank slate without national regulation of air pollution, it may be unsurprising that such gains could be achieved cost-effectively. As further improvements may be more incremental and come at higher costs, or involve altogether different challenges such as climate change, the weighing of costs against monetized benefits may warrant renewed consideration.

© Arnold & Porter Kaye Scholer LLP 2026 All Rights Reserved. This Advisory is intended to be a general summary of the law and does not constitute legal advice. You should consult with counsel to determine applicable legal requirements in a specific fact situation.