This paper studies horizontal mergers in vertically related markets. In a two-level Cournot model, with an intermediate and a final market, we show that downstream mergers inducing size effects are, ceteris paribus, more profitable than upstream ones. Moreover, a merger at one level reduces the...

This article attempts to determine the optimal antitrust policy against price-fixing when competition authorities imperfectly observe firms' behaviour. By investigating or auditing on markets, authorities can detect collusion. We show that the strenght of investigations depends on the...

We analyze the incentives for a controlling shareholder to acquire silent or controlling shares in a competitor. When it occurs, the acquisition is detrimental to minority shareholders of his firm, or to the target, or even to both. The ownership structure of firms turns out to be a key...

[eng] Collusion deterrence and efficiency of two regimes of fines. . Within a Principal Agent Model, we characterize the optimal policy of an agency in charge of competition policy. We consider a situation of asymmetric information concerning the cost of production between the agency and the...

In this article, we analyze the characteristics of legal thresholds crossings in France during the years 2001 through 2003. Our data set created using the publications of the financial authorities and economic and financial data from Bloomberg comprises a total of 2.396 operations and displays a...

We analyze horizontal mergers in vertically related industries. In a successive Cournot oligopoly model, we first compare the profitability of mergers in the upstream and in the downstream sectors. We characterize conditions on the concavities of the input supply function and the final demand...