Clayton act providesAny person who shall be injured in his business or property by reason of anything forbidden in the antitrust laws may sue therefore in any district court of the united states in the district in which the defendant resides or is found or has an agent, without respect to the amount in controversy, and shall recover threefold the damages by him sustained, and the cost of suit, including a reasonable attorney’s fee.

The original version of the Sherman act contained a similar provision for treble damages under private antitrust legislation. This was superseded by section 4 of the Clayton act. Treble damages, therefore, have always been part of the U.S. antitrust laws.

The treble damage provision provides individuals and firms with a powerful incentive to enforce the antitrust laws privately. It is for this reason that many of the antitrust cases we discuss in later chapters are private antitrust suits, not suits begun by either the justice department or the federal trade commission. But the issue of private enforcement of the antitrust laws is complex, and is the focus of much current controversy. Does the treble damage provision provide a way for firms to use private antitrust suits to harass large, efficient rivals, with a net effect or worsening market performance? This is an important policy question to which we will return in Chapter 18.