Liability Insurance under the Negligence Rule

We analyze the efficiency properties of the negligence rule with liability insurance, when the tort-feasor's behavior is imperfectly observable both by the insurer and the court. Efficiency is shown to depend on the extent to which the evidence is informative, on the evidentiary standard for finding negligence, and on whether insurance contracts can condition directly on the same evidence as used by courts to assess behavior. When evidence is not directly contractible, the negligence rule with compensatory damages is generally inefficient and can be improved by decoupling liability from the harm suffered by the victim.Negligence, liability insurance, evidentiary standard, moral hazard, judicial error, decoupling, prudence

Incentives for Partial Acquisitions and Real Market Concentration

We analyze the incentives of a controlling shareholder of a firm to acquire, directly or indirectly through his firm, shares in a competitor. We charaterize the conditions under which these partial acquisitions as well as the equilibrium toehold and its nature: controlling or silent. We find that while this shareholder gains, the acquisition is detrimental to minority shareholders of his firm, or of the target, or even of both. We show that the incentives are enhanced if the dominant shareholder initially holds silent stakes in rivals while controlling interests may discourage them. Moreover, we find that partial acquisitions always lead to a decrease in the joint profit of the two firms involved, and an increase in competitor's profits as the market becomes less competitive.horizontal partial acquisitions ; real market concentration ; dominant shareholder ; minority shareholders ; silent interests.

Real market concentration through partial acquisitions

We study horizontal partial acquisitions in an oligopolistic industry in the absence of synergies. Contrary to existing results, we find that a dominant shareholder may choose to acquire shares in a competitor although the aggregate profit of the group of firms under his control, and even the greater group of firms in which he has a stake, is reduced. This is due to a “favorite” effect: after the acquisition, the dominant shareholder will favor the firm in which he eventually holds the relatively higher share to the detriment of shareholders of the other firms. For this reason, a block of shares can be bought at a discount when the value of the firm of the initiator decreases post acquisition. Moreover, we show that the existence of initial silent toeholds in rivals enhances the incentive for a dominant shareholder to buy shares in other firms in the industry, whereas controlling ones may discourage them.Horizontal partial acquisitions; Real market concentration; Dominant shareholder; Minority shareholders; Silent interests

Concurrence en contrats, anti-sélection et structure d'information

This paper generalizes the work of Rothschild and Stiglitz [1976], and is dealing with a game where two principals compete for an agent, when the agent has private information. The studied game has an efficient equilibrium, when the payoff of the principal does not depend on private information. Competition in markets with asymmetric information does not always imply loss of efficiency. An explain in terms of type of uncertainty is proposed.

Does Entry Improve Welfare ? A General Equilibrium Approach of Competition Policy

We consider a general equilibrium model under imperfect competition. Firms have constantreturns, they are price taker in the input market and compete à la Cournot in theproduct market. We assume a representative consumer exists. We show that an increase inthe number of firms of a given market does not always improve welfare, challenging thecommon idea according to which mergers with no cost synergy are not desirable for theconsumer.

A Note on The Pareto Efficiency of General Oligopolistic Equilibria

This note shows that a general oligopolistic equilibrium (GOLE), a notionrecently introduced in the literature by Neary, may be Pareto-efficient. Consequently,at a GOLE, the allocation of resources can be identical to thatof a competitive equilibrium. We also propose a characterization of Paretoefficientgeneral oligopolistic equilibria.

Does entry improve welfare? A general equilibrium approach to competition policy

We consider a simple general equilibrium model with imperfect competition. Firms are price taker in the input market and compete à la Cournot in some or all of the product markets (their technology displays constant returns to scale). We show that an increase in the number of firms does not always improve welfare. We also provide a characterization in terms of mark-up rates of the sectors for which entry is welfare enhancing. Thus, this paper challenges the common idea that mergers with no cost synergy are not desirable for consumers.Cournot competition, competition policy, general equilibrium and imperfect competition, effciency

Prevention in insurance markets

This paper considers a competitive insurance market under moral hazard and adverse selection, in which preventive efforts and self-protection costs are unobservable by insurance companies. Under reasonable assumptions, the conclusions of Rothschild and Stiglitz (1976) are preserved in our context even if it involves moral hazard. The riskier agents in equilibrium, who would also be the riskier agents under perfect information, receive their moral hazard contract. For other agents, adverse selection reduces coverage, increasing likewise their preventive effort with respect to the hidden-action situation.