What can merger retrospectives tell us?An assessment of European mergers

In this review of retrospective European merger studies we provide a discussion of the price effect of analysed mergers and examine whether the antitrust agency made the right decisions. We find that remedied mergers, on average, were not followed by a price-increase, suggesting that, in our sample, merger interventions were effective at eliminating problems. High market concentration was more likely to lead to higher post-merger prices, although remedies were able to reduce post-merger price-increases, even in concentrated markets. We look at a number of reasons why prices may increase post-merger and find little evidence of genuine agency errors.