This paper summarizes the peculiarities of online markets and discusses recent antitrust cases related to online markets. Following a brief description of the online markets' characteristics and potential tendencies for concentration the paper first discusses the antitrust allegations and...

We analyze the competitive effects of backward vertical integration by a partially vertically integrated firm that competes with non-integrated firms both upstream and downstream. We show that vertical integration is procompetitive under fairly general conditions. It can be anticompetitive only...

We investigate the effect of a vertical merger on downstream firms' ability to collude in a repeated game framework. We show that a vertical merger has two main effects. On the one hand, it increases the total collusive profits, increasing the stakes of collusion. On the other hand, it creates...