Umbrella Damages: Toward A Coherent Antitrust Policy

Price‐fixing cartels usually do not involve all members of an industry. To the extent that the nonconspiring industry members set their prices under the price umbrella of the cartel, the customers of the nonconspiring firms suffer overcharges just like customers of the conspiring firms. Whether these so‐called umbrella plaintiffs have standing to sue for antitrust damages is an unresolved policy question, because the Supreme Court has not spoken on “umbrella damages.” In this article, we identify the judicial concerns regarding umbrella damage claims, which can be traced to Mid‐West Paper and Petroleum Products Antitrust Litigation. These decisions raise concerns that the fact of injury is conjectural and the measurement of the damages is speculative. We first review the divided judicial treatment of standing for umbrella plaintiffs. Next, we describe the economics of umbrella pricing, which reveals that umbrella claims are not inherently conjectural. We then examine the econometric analysis necessary to estimate damages, demonstrating that umbrella damage estimates are not inherently speculative. We also examine some difficulties that exist in damage estimation generally and for umbrella plaintiffs in particular. Finally, we argue that granting standing to umbrella plaintiffs is consistent with the goals of antitrust policy. (JEL L1, L4, K2)