Environmental Regulation, Imperfect Competition, and Market Spillovers: The Impact of the 1990 Clean Air Act Amendments on the US Oil Refining Industry

This working paper estimates the impact of Clean Air Act restrictions on refined petroleum products on refining costs, product prices, and consumer welfare.



May 10, 2023


Richard L. Sweeney


Working Paper

Reading time

1 minute


The 1990 Clean Air Act Amendments imposed extensive restrictions on refined petroleum product markets, requiring select end users to purchase new cleaner versions of gasoline and diesel. I estimate the impact of this intervention on refining costs, product prices and consumer welfare. Isolating these effects is complicated by several challenges likely to appear in other regulatory settings, including overlap between regulated and non-regulated markets and deviations from perfect competition. Using a rich database of refinery operations, I estimate a structural model that incorporates each of these dimensions, and then use this cost structure to simulate policy counterfactuals. I find that the policies increased gasoline production costs by 7 cents per gallon and diesel costs by 3 cents per gallon on average, although these costs varied considerably across refineries. As a result of these restrictions, consumers in regulated markets experienced welfare losses on the order of $3.7 billion per year, but this welfare loss was partially offset by gains of $1.5 billion dollars per year among consumers in markets not subject to regulation. The results highlight the importance of accounting for imperfect competition and market spillovers when assessing the cost of environmental regulation.


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Richard L. Sweeney

Boston College

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