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

摘要

This article surveys, discusses and classifies methods for ex-post evaluation of the efficiency ofncompetition authorities: court appeals, peer reviews, case studies, event studies, (authorities’ own)nbottom-up calculations of consumer gains, deadweight-loss estimates, cross-country panel studiesnetc. Based on empirical estimates from other types of studies and on a simple oligopoly model,none conclusion is that many bottom-up calculations are based on exaggerated estimates of gainsnfrom cartel enforcement, relative to those from merger enforcement. Another conclusion is thatnauthorities’ ex-post self evaluations are of limited value, relative to external evaluations.