This paper provides a comparative analysis of methods for the empirical ex post evaluation of merger control decisions. It develops a competition-policy oriented framework of assessment criteria for the leading evaluation methods and applies them to structural modeling and simulation, differences-in-differences methods, event studies as well as survey-based methods. It concludes that a method-mix is recommendable, however, under the exclusion of event studies that fail to secure a minimum level of reliability regarding the evaluation results. Furthermore, it warns against overly optimistic expectations about the effects of systematic impact evaluations of merger decisions.
empirical methods of industrial organization merger control competition policy antitrust decisions comparative analysis