In the U.S., private antitrust enforcement plays a large role in the general enforcement scheme of the antitrust laws. Companies that plead guilty or are convicted of price-fixing generally pay fines but not restitution to victims—private litigation is assumed to be sufficient to compensate victims. The threat of treble damages in private actions (both individual and class actions) is significant, and often aggrieved parties can win more in damages than the government is able to recover and fine. And the chance to “detreble” damages by cooperating with plaintiffs can play a large role in a company’s decision to participate in the Antitrust Division’s leniency program.

The effects of such private suits are blunted in the European Union.