Before-and-After Theory Law and Legal Definition

In the context of Antitrust law, before-and-after theory is a method of ascertaining damages for lost profits, where the plaintiff's profits are examined before, during, and after the violation in order to analyze the reduction in profits due to the defendant's violation. This is also known as the before-and-after method. The before-and-after theory looks at the plaintiff's net profits prior to and after the injury period and brings the plaintiff’s earnings during the injury period up to the same average level as the earnings during the non-injury periods.