The paper develops a four-step framework to detect anticompetitive horizontal mergers. In the first step, an estimate of the impact of the merger on the market price needs to be derived. Subsequent, the second step of the framework has to assess whether such a predicted price increase would be...

The paper aims at assessing the costs and benefits of antitrust enforcement. The analysis starts with an investigation of why competition is typically worth protecting followed by a collection of empirical evidence which shows that competition actually needs protection by antitrust policy in...

We analyze the effects of downstream firms' acquisition of pure cash flow rights in an efficient upstream supplier when all firms compete in prices. With an acquisition, downstream firms internalize the effects of their actions on their rivals' sales. Double marginalization is enhanced. Whereas...

Die aktuelle Diskussion um die Novellierung der deutschen Pressefusionskontrolle macht deutlich, welche Relevanz medienökonomische Fragestellungen haben. Was jedoch bei dieser Diskussion häufig vernachlässigt wird, ist die intensive Betrachtung der Ökonomischen Besonderheiten von...

Under ex ante access regulation entrants often claim that access fees are excessive. I show that this is only the case if further entry is admitted. If the entrant is protected from further entry it would agree with the incumbent upon a strictly positive access fee which may exceed the efficient...

Within the last three years, Google has acquired YouTube and DoubleClick and has attempted to control part of Yahoo!'s search advertising business. Two of the deals have not raised antitrust concerns by competition authorities. I review these deals with a focus on consumer welfare. Consumers are...

The paper characterises the building blocks of a framework to enforce antipredation rules and subsequently evaluates selected enforcement options in a Cournot-type duopoly predation model. Differentiating between a no rule approach, an ex ante approach and two ex post approaches, it is shown...

The paper provides a comprehensive survey of the economics behind the fight against hard core cartels. Differentiating between four subsequent stages - characterisation, welfare effects, enforcement and evaluation - the paper pays particular attention to cartel detection methods, the derivation...