Pauline Affeldty, Tomaso Dusoz and Florian Szücs on ‘25 Years of European Merger Control’ (2019) DIW Berlin Discussion Paper 179

The first European merger control regime came into force in 1990. Since then, merger control has evolved significantly. This paper, available here, employs a new dataset, comprising all merger cases until 2014 that led to a decision by DG Comp (more than 5,000 individual decisions). The goal of the paper is to evaluate the time dynamics of the European Commission’s decision procedures. Specifically, the paper assesses how consistently different arguments related to so-called structural market parameters – market shares, concentration, likelihood of entry and foreclosure – were deployed by the Commission over time. The paper first estimates the probability of intervention as a function of merger characteristics. It finds that the existence of barriers to entry, increases in concentration and, in particular, the share of product markets with competitive concerns are positively associated with intervention by the Commission. After the reform of 2004, an effects-based approach centred on a clearly stated theory of harm became a cornerstone of EU merger…

Volker Nocke and Michael D. Whinston on ‘Concentration Screens for Horizontal Mergers’ (2020) NBER Working Papers no 27533

Concentration measures play a central role in merger analysis. Existing guidelines identify various presumptions – both safe harbours and presumptions of anticompetitive effects – based on the level of the post-merger Herfindahl index and of the change that the merger induces in that index. These presumptions have a significant impact on agency decisions, especially in screening mergers for further review. However, the basis for these screens, in both form and level, remains unclear. The authors of this paper, available here, show that there is both a theoretical and an empirical basis for focusing solely on changes in the Herfindahl index, and ignoring its level, in screening mergers for whether their unilateral effects will harm consumers. The authors also argue that the levels at which the presumptions currently are set may allow mergers to proceed that cause consumer harm. Section 2 reviews concentration screens in various versions of the US Horizontal Merger Guidelines. The first version of the Merger Guidelines –…