On 20 June 2008, TILEC organized a workshop on the issue of private enforcement of competition law. Indeed, the European Commission has now issued its long-awaited white paper onantitrust damages and the wisdom, as well as the modalities, of the suggested facilitation of victims' access to compensation is much debated. Eddy de Smijter (European Commission) explained the policy choices advocated by the Commission. Jeroen Kortmann (University of Amsterdam) provided the audience with a tort-law perspective on the subject and showed how problematic some aspects of the proposal could be, given the myriads of legal solutions in force in the various Members-States. Turning to the more specific issue of the assessment of damages, Frank Verboven (KU Leuven) insisted on the so-called output effect (the welfare loss associated to those units which should have been sold absent the infringement), which seems problematic to estimate. Jan Tuinstra (University of Amsterdam) stressed the complications introduced by the presence of several layers of intermediate purchasers or suppliers. Wieland Müller (TILEC) suggested a general framework for the determination and practical estimation of the total harm to downstream firms and final consumers caused by e.g. price fixing upstream.