The purpose of this article is to analyze how the presence of a competitive fringe, composed by price taker firms, can affect the sustainability of collusive equilibria. Our starting point is that there exists a diffused misunderstanding about its strategical role as collusive minus factor. We...

In this paper, we tackle the dilemma of pruning versus proliferation in a vertically differentiated oligopoly under the assumption that some firms collude and control both the range of variants for sale and their corresponding prices, likewise a multiproduct firm. We analyse whether pruning...

Successful upstream collusion must satisfy both the incentive constraint (keeping cartel members in line) and the compensation constraint (preventing lawsuits from downstream firms). Our analysis shows that there is a non-monotonic and inverted U-shaped relationship between cartel incidence and...

This paper introduces a number of game-theoretic tools to model collusive agreements among firms in vertically differentiated markets. I firstly review some classical literature on collusion between two firms producing goods of exogenous different qualities. I then extend the analysis to a...

In this paper, we tackle the dilemma of pruning versus proliferation in a vertically differentiated oligopoly under the assumption that some firms collude and control both the range of variants for sale and their corresponding prices, likewise a multiproduct firm. We analyse whether pruning...

Algorithmic collusion is a hot topic within antitrust circles in Europe, US and beyond. But some economists downplay algorithmic collusion as unlikely, if not impossible. This paper responds to these criticisms by pointing to new emerging evidence and the gap between law and this particular...

Classic artificial intelligence (Q-learning) algorithms have been capable of consistently learning supra-competitive pricing strategies in infinitely repeated Nash-Bertrand pricing games without human communication. Such algorithms have been able to converge due to the temporal correlation of...

This paper undertakes a critical review of the prospect that self-learning pricing algorithms will lead to widespread collusion independently of the intervention and participation of humans. There is no concrete evidence, no example yet, and no antitrust case that self-learning pricing...

This paper studies ATM coalitions in retail banking. We ask when it is profitable for banks to make agreements which ban direct ATM transaction fees. In the case of a coalition banks loose income from ATM transactions but relax competition in the banking market. We find that such agreements are...