Benefits and Costs of the Clean Air Act
Second Prospective Study - 1990 to 2020
On March 1, 2011, EPA released the Second Prospective Study estimating the benefits and costs of the 1990 Clean Air Act Amendments. Among other insights, the study found that
1. The direct benefits of the 1990 Clean Air Act Amendments and associated programs significantly exceed their direct costs, which means economic welfare and quality of life for Americans were improved by passage of the 1990 Amendments.
The wide margin by which benefits exceed costs combined with extensive uncertainty analysis suggest it is very unlikely this result would be reversed using any reasonable alternative assumptions or methods.
2. The economy as a whole is also stronger with 1990 Clean Air Act Amendment programs as cleaner air leads to better health and productivity for American workers and less money spent on health care to treat air pollution-related health problems.
Economy-wide modeling shows that long-term economic growth is greater and American household economic welfare is improved because benefits such as fewer sick days and lower medical costs more than offset the economy-wide cost of investing in air pollution control.
Two versions of the study report were published: a full report which integrates all the major analytical components of the study and provides full documentation of the study and its results, and a summary report which conveys the essential design and results of the study. Copies of the integrated report and the summary report can be downloaded by following the links below:
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The Benefits and Costs of the Clean Air Act from 1990 to 2020: Summary Report (PDF) (34 pp, 1.3 MB) - Washington, D.C., March 2011
The Benefits and Costs of the Clean Air Act from 1990 to 2020 (PDF) (238 pp, 4 MB) - Washington, D.C., Updated final report April 2011.
The major analytical components of the Second Prospective Study are shown in Figure 1. For some components of the study, such as Scenario Development and Benefit-Cost Comparison, the full report of the Second Prospective Study provides full documentation of the methods and results. For other major components of the study, supporting technical reports are available which provide additional technical information.
Supporting technical reports which have been released as final documents are available for download at the links below. Those major analytical component technical reports which are available only in draft are marked as [PENDING] on this page, and download links to final versions of these technical reports will be posted on this page as they become available. Preliminary review drafts of these reports are available for download now on the Second Prospective Study external review web page, though it is important to note that the methods and results documented in these preliminary review drafts may have been superseded by methods and results documented in the final full report and/or in more recent technical memoranda, which are also available on the external review web page.
Some analytical components also have additional, minor supporting documents such as proposed methodology white papers - which were made public as part of the external expert review of the Second Prospective Study. Electronic copies of these minor supplementary documents are also available for download on the Second Prospective Study external review web page.
Emissions
- Final report: Emissions Projections for the Clean Air Act Second Section 812 Prospective Analysis Final Report (PDF)(216pp, 1.1 MB)
Direct Cost
- Final report: Direct Cost Estimates for the Clean Air Act Second Section 812 Prospective Analysis: Final Report (PDF) (327pp, 1.7 MB)
Air Quality Modeling
- Final memorandum to the files: Documentation of Second Prospective Study air quality modeling (PDF) (206 pp, 3.3 MB)
Health and Welfare Effects (including Economic Valuation)
- Final Report: Health and Welfare Benefits Analyses to Support the Second Section 812 Benefit-Cost Analysis of the Clean Air Act: Final Report (PDF) (164pp, 2.5 MB)
HAP Case Study
- Final report main text: Air Toxics Case Study - Health Benefits of Benzene Reductions in Houston, 1990-2020, Final Report (PDF) (90 pp, 1.9 MB)
- Final report appendices: Air Toxics Case Study - Health Benefits of Benzene Reductions in Houston, 1990-2020, Final Report - Appendices (PDF) (255 pp, 6.9 MB)
Uncertainty Analysis
- Draft report: Uncertainty Analyses to Support the Second Section 812 Benefit-Cost Analysis of the Clean Air Act: Draft Report (PDF) (200 pp, 4.0 MB)
- Final report pending. (will be posted when available)
Macroeconomic Modeling
- Draft report: 812 Economic Analyses Using the EMPAX-CGE Modeling System: Revised Draft Report (PDF) (38pp, 276k)
- Final report pending. (will be posted when available)