Price-Quantity Competition of Farsighted Firms: Toughness vs. Collusion
This paper compares the market equilibria in a differentiated industry under Cournot, Bertrand, and monopolistic competition. This is accomplished in a one-sector economy where consumers are endowed with separable preferences. When firms are free to enter the market, monopolistically competitive firms charge lower prices than oligopolistic firms, while the mass of varieties provided by the market is smaller under the former than the latter. If the economy is sufficiently large, Cournot, Bertrand and Chamberlin solutions converge toward the same market outcome, which may be a competitive or a monopolistically competitive equilibrium, depending on the nature of preferences.
A new concept of equilibrium in secure strategies (EinSS) in non-cooperative games is presented. The EinSS coincides with the Nash Equilibrium when Nash Equilibrium exists and postulates the incentive of players to maximize their profit under the condition of security against actions of other players. The new concept is illustrated by a number of matrix game examples and compared with
other closely related theoretical models. We prove the existence of equilibrium in secure strategies in two classic games that fail to have Nash equilibria. On an infinite line we obtain the solution in secure strategies of the classic Hotelling’s price game (1929) with a restricted reservation price and linear transportation costs. New type of monopolistic equilibria in secure strategies are discovered in the Tullock Contest (1967, 1980) of two players.
We examine an equilibrium concept for 2-person non-cooperative games with boundedly rational agents which we call Nash-2 equilibrium. It is weaker than Nash equilibrium and equilibrium in secure strategies: a player takes into account not only current strategies but also all profitable next-stage responses of the partners to her deviation from the current profile that reduces her relevant choice set. We provide a condition for Nash-2 existence in finite games and complete characterization of Nash-2 equilibrium in strictly competitive games. Nash-2 equilibria in Hotelling price-setting game are found and interpreted in terms of tacit collusion.
We study Bertrand competition models with incomplete information about rivals' costs, where uncertainty is given by independent identically distributed random variables. It turns out that Bayesian Nash equilibria of the simplest of these games are described as Cournot prices. Then we discuss general conditions when Cournot prices give Bayesian Nash equilibria for Bertrand games with incomplete information about rivals' costs.
The paper studies a market of horizontally differentiated good under increasing return to scale and exogenous number of firms. Three concepts of equilibria are compared: Cournot, Bertrand and monopolistic competition. Under fairly general assumptions on consumer’s preferences, it is shown that Lerner index is the highest in Cournot case, monopolistic competition provides the lowest one and Bertrand equilibrium takes intermediate position. When the number of firms N increases, both oligopolistic equilibria converge to monopolistic competitive equilibrium with rate 1 / N . Thus the study generalizes the similar results on markets of homogeneous goods.
We develop a model of monopolistic competition that accounts for consumers' heterogeneity in both incomes and preferences. This model makes it possible to study the implications of income redistribution on the toughness of competition. We show how the market outcome depends on the joint distribution of consumers' tastes and incomes and obtain a closed-form solution for a symmetric equilibrium. Competition toughness is measured by the weighted average elasticity of substitution. Income redistribution generically affects the market outcome, even when incomes are redistributed across consumers with different tastes in a way such that the overall income distribution remains the same.
We consider a model of location-price competition between two firms, located on the circle. Nash equilibrium, equilibrium in secure strategies, and Nash-2 equilibrium are compared. We demonstrate that Nash-2 equilibrium exists for any locations of firms. The set of Nash-2 equilibria is treated as tacit collusion.
We consider certain spaces of functions on the circle, which naturally appear in harmonic analysis, and superposition operators on these spaces. We study the following question: which functions have the property that each their superposition with a homeomorphism of the circle belongs to a given space? We also study the multidimensional case.
We consider the spaces of functions on the m-dimensional torus, whose Fourier transform is p -summable. We obtain estimates for the norms of the exponential functions deformed by a C1 -smooth phase. The results generalize to the multidimensional case the one-dimensional results obtained by the author earlier in “Quantitative estimates in the Beurling—Helson theorem”, Sbornik: Mathematics, 201:12 (2010), 1811 – 1836.
We consider the spaces of function on the circle whose Fourier transform is p-summable. We obtain estimates for the norms of exponential functions deformed by a C1 -smooth phase.