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Quis Custodiet Ipsos Custodes? or Measuring and Evaluating the Effectiveness of Competition Enforcement

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This article surveys, discusses and classifies methods for ex-post evaluation of the efficiency of competition authorities: court appeals, peer reviews, case studies, event studies, (authorities’ own) bottom-up calculations of consumer gains, deadweight-loss estimates, cross-country panel studies etc. Based on empirical estimates from other types of studies and on a simple oligopoly model, one conclusion is that many bottom-up calculations are based on exaggerated estimates of gains from cartel enforcement, relative to those from merger enforcement. Another conclusion is that authorities’ ex-post self evaluations are of limited value, relative to external evaluations.

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Correspondence to Mats A. Bergman.

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“Who watches the guardians?”, by Juvenal, 2nd century Roman poet and critic.

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Bergman, M.A. Quis Custodiet Ipsos Custodes? or Measuring and Evaluating the Effectiveness of Competition Enforcement. De Economist 156, 387–409 (2008).

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