The conventional wisdom is that private antitrust enforcement lacks any value. Indeed, skepticism of private enforcement has been so great that its critics make contradictory claims. The first major line of criticism is that private enforcement achieves too little—it does not even minimally compensate the actual victims of antitrust violations and does not significantly deter those violations. A second line of criticism contends that private enforcement achieves too much—providing excessive compensation, often to the wrong parties, and producing overdeterrence. This Article undertakes the first ever systematic evaluation of these claims. Building upon original empirical work and theoretical inquiry by the authors, and an assessment of the s...