Exxon Shipping Co. v. Baker, 554 U.S. 471 (2008)
Exxon Shipping Co. v.
Under federal maritime common law, are punitive damages available for reckless conduct causing mass environmental harm, and if so, what limits apply to the size of punitive awards; and does the Clean Water Act preempt private punitive damages in this context?
As a matter of federal maritime common law, punitive damages are available in appropriate cases but are limited to a 1:1 ratio to compensatory damages as a fair upper bound to ensure predictability and proportionality. The Clean Water Act does not preempt private claims for punitive damages in maritime tort litigation. The Court did not reach any constitutional due process limit, deciding instead on maritime common-law grounds; and due to an even division on the corporate vicarious liability question, the Ninth Circuit's ruling allowing punitive damages against Exxon based on managerial misconduct remained in place without a precedential Supreme Court resolution.
The punitive damages award of $2.5 billion was excessive under federal maritime common law. The Court imposed a 1:1 punitive-to-compensatory damages cap in maritime cases and reduced punitive damages to $507.5 million (equal to the compensatory award). The Court further held that the Clean Water Act does not preempt private punitive damages in maritime tort cases. The Court was equally divided on whether Exxon's liability for punitive damages could be based on the acts of its managerial employees, leaving the Ninth Circuit's allowance of such vicarious punitive liability undisturbed.
Exxon Shipping Co. v. Baker is essential for understanding punitive damages and the interplay between statutory regimes and judge-made maritime law. It establishes a clear, administrable maritime rule capping punitive damages at a 1:1 ratio to compensatory damages—distinct from, and not replacing, the constitutional guideposts in non-maritime cases. The case preserves private punitive remedies alongside governmental enforcement under the Clean Water Act, clarifies that constitutional due process need not be reached where maritime common law supplies an adequate rule, and highlights the Court's institutional concerns with variability and fairness in punitive awards. For law students, it is a leading case at the intersection of Torts, Remedies, and Admiralty, frequently tested to probe understanding of punitive damages frameworks, preemption, and the judiciary's role in crafting federal common law.