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...

We investigate the effects of passive backward acquisitions in their efficient upstream supplier on downstream firms' ability to collude in a dynamic game of price competition with homogeneous goods. We find that passive backward acquisitions impede downstream collusion. The main driver of our...

Tacit collusion reduces welfare comparably to explicit collusion but remains mostly unaddressed by antitrust enforcement which greatly depends on evidence of explicit communication. We propose to target specific elements of firms' behavior that facilitate tacit collusion by providing...

Within a simple model of differentiated oligopoly, we show that tacit collusion may be prevented by the threat of nationalising a private firm coupled with the appropriate choice of the weight given to private profits in the maximand of the nationalised company. We characterise the properties of...

This is a survey of the economic principles that underlie antitrust law and how those principles relate to competition policy. We address four core subject areas: market power, collusion, mergers between competitors, and monopolization. In each area, we select the most relevant portions of...

In many cases, collusive agreements are formed by asymmetric firms and include only a subset of the firms active in the cartelized industry. This paper endogenizes the process of cartel formation in a numeric simulation model where firms differ in marginal costs and production technologies. The...

We analyze strategic leaks due to spying out a rival’s bid in a first-price auction. Such leaks induce sequential bidding, complicated by the fact that the spy may be a counterspy who serves the interests of the spied at bidder and reports strategically distorted information. This ambiguity...

This paper analyzes the impact vertical integration has on upstream collusion when the price of the input is linear. As a first step, the paper derives the collusive equilibrium that requires the lowest discount factor in the infinitely repeated game when one firm is vertically integrated. It...

We examine the effects of (passive) cross-holdings in the downstream market on the sustainability of upstream collusion. We consider two competing vertical chains with downstream Cournot and homogeneous goods. Each downstream firm holds a (symmetric) non-controlling share of its rival. We find...