The roundtable focused on the recurring synergies that mergers sometimes create. These synergies, or “efficiencies,” can have very potent beneficial effects but are devilishly difficult to identify and measure. The difficulty arises mainly because dynamic efficiencies occur over time and can be abstract in nature. They therefore do not lend themselves to the “snapshot” analysis that is used to assess static efficiencies. The Committee discussed various types of dynamic efficiencies, focusing on those that facilitate or encourage innovation. In general, cases in which dynamic efficiencies play a significant role are relatively rare. There was general agreement that proving a specific likelihood of claimed dynamic efficiencies and measuring their impact are difficult tasks for which there are no easy approaches. At present, quantitative assessments do not appear to be feasible. Furthermore, many competition enforcement agencies will not take dynamic efficiencies into account unless they are merger-specific (i.e., unlikely to occur absent the merger), substantial, and verifiable, which does not make it any easier for merging parties to succeed with dynamic efficiency claims. Some agencies, however, have accepted qualitative dynamic efficiency claims and have had success in assessing them to their satisfaction despite alack of quantification. This document comprises proceedings in the original languages of a Roundtable on Dynamic Efficiencies in Merger Analysis and Competition Policy, held by the Competition Committee in June 2007.