(1) Université Mohamed Premier, Faculté des Sciences, Dépt de Physique, (L.E.A.A), Route Sidi Maafa BP 524, Oujda, Morocco. (2) Laboratoire d’Analyse et d’Architecture des Systèmes (LAAS-CNRS), 7 Avenue du colonel Roche, Toulouse 31077, France. * E. mail : [email protected] This work has been supported by : •le comité Franco-Marocain ‘Action Intégrée’, N° MA/03/78, •le Programme Thématique d’Ap...

This paper studies farsighted behavior of firms in an oligopolistic market to form a dominant cartel, which has a power to set and control the price in the market. The von Neumann-Morgenstern stable set is adopted as the solution concept. In contrast to the literature, we do not assume a priori the optimal pricing behavior of the cartel; rather, we show that such behavior arises from the result...

We analyze an equilibrium search model in a duopoly setting with bilateral heterogeneities in production and search costs in which firms can advertise by announcing price and location. We study existence, stability, and comparative statics in such a setting, compare the duopolistic advertising level to the socially optimal level, and find conditions in which a duopolist advertises more or less ...

In a (generalized) symmetric aggregative game, payoffs depend only on individual strategy and an aggregate of all strategies. Players behaving as if they were negligible would optimize taking the aggregate as given. We provide evolutionary and dynamic foundations for such behavior when the game satisfies supermodularity conditions. The results obtained are also useful to characterize evolutiona...

Concentration-based thresholds for horizontal mergers, such as those in the US Horizontal Merger Guidelines, play a central role merger analysis but their basis remains unclear. We show that there is both theoretical and an empirical focusing solely on change concentration, ignoring its level, screening mergers whether unilateral price effects will harm consumers. also argue current threshold l...

American industries have grown more concentrated over the last 40 years. In absence of productivity innovation, this should lead to price hikes and output reductions, decreasing consumer welfare. With US census data from 1972 2012, I use disentangle revenue output. Industry-level estimates show that concentration increases are positively correlated real growth, uncorrelated with changes overall...

This paper investigates competition between health insurance companies under different financing regulations. We consider two alternatives advanced in recent German health care reform discussions: competition by contribution rates (health contributions) and by fees (health premia). We find that contribution rate competition yields lower company profits and higher consumer welfare than premia co...

We develop a model of endogenous mergers to study their dynamic process. Firms choose whether, when, and with whom to merge. Two necessary conditions are identi…ed for mergers to occur: …rm heterogeneity and negative demand shocks. We show that mergers are strategic complements and therefore tend to occur in waves. Moreover, some mergers occur for strategic reasons in order to precipitate furth...

For Bertrand duopoly with linear costs, we establish via a single counterexample that: (i) A new monotone transformation of the firms’ profit functions may lead to the supermodularity of transformed profits when the standard log and identity transformations both fail, and (ii) Topkis’s notion of critical sufficient condition for monotonicity of a Bertrand firm’s best-reply correspondence cannot...

We investigate the issue of strategic substitutability/complementarity in differential games. We prove that instantaneous best replies exist if Hamiltonian functions are multiplicative in the control variables. Otherwise, if the Hamiltonians are addively separable w.r.t. controls, a dominant strategy emerges for each player. In this case, however, imposing stationarity on the differential equat...