This paper studies competition in the German market for mobile telecommunications, motivated by recent suggestions that T-Mobile and Vodafone possess a position of collective dominance. Allegedly, their position of joint dominance is secured through a combination of first-mover advantages and...

Katz (1987), DeGraba (1990), and Yoshida (2000) have formulated theories that price discrimination bans in intermediary goods markets tend to have positive effects on allocative, dynamic and productive efficiency, respectively. We show that none of these results is robust vis-à-vis endogenous...

We re-examine the view that a ban on price discrimination in input markets is particularly desirable in the presence of buyer power. This argument crucially depends on an inverse relationship between downstream firms' profits and the uniform input price. Assuming different input efficiencies...