Coalition-proof supply function equilibria in oligopoly

In an industry where firms compete via supply functions, the set of equilibrium outcomes is large. If decreasing supply functions are ruled out, this set is reduced significantly, but remains large. Specifically, the set of prices that can be sustained by supply function equilibria is the interval between the competitive price and the Cournot price. In sharp contrast, when the number of firms is above a threshold we identify (e.g., three if demand is linear), only the Cournot outcome can be sustained by a coalition-proof supply function equilibrium.Publicad

Coalition-proof supply function equilibria in oligopoly

In an industry where firms compete via supply functions the set of market outcomes that can arise is large. If decreasing supply functions are ruled out, the set of equilibrium outcomes reduces somewhat, but it remains large: any price between the competitive price and the Cournot price can be sustained by a supply function equilibrium. In sharp contrast, this multiplicity disappears when firms take into account the gains they can attain by coordinating their actions: if the number of firms is above a threshold we identify (e.g., three if demand is linear), then the Cournot equilibrium is the unique outcome that can be sustained by a coalition-proof supply function equilibrium

Mixed Duopoly with Price Competition

This paper examines coalition-proof Nash equilibria (CPNE) of a mixed duopoly with price competition where the public firm meets all the demand coming to it. If the private firm is free to supply less than demand, then the unique CPNE involves the competitive price. If however the private firm also has to supply all its demand, then the set of CPNE prices turns out to be an interval, with prices ranging from the socially optimal one, to the price under complete privatization.Mixed duopoly; coalition-proof Nash equilibrium; price competition

Coalition-proof supply function equilibria under capacity constraints

Whereas in the absence of capacity constraints the Cournot outcome is the unique coalition-proof supply function equilibrium outcome, the presence of capacity constraints may enlarge the set of equilibrium outcomes. Interestingly, if capacities are sufficiently asymmetric the new equilibrium prices are below the Cournot price. These results have important implications for merger and privatization policies: specifically, capacity divestiture will not necessarily imply lower market prices

COALITION-PROOF SUPPLY FUNCTION EQUILIBRIA UNDER CAPACITY CONSTRAINTS

Whereas in the absence of capacity constraints the Cournot outcome is the unique coalition-proof supply function equilibrium outcome, the presence of capacity constraints may enlarge the set of equilibrium outcomes. Interestingly, if capacities are sufficiently asymmetric the new equilibrium prices are below the Cournot price. These results have important implications for merger and privatization policies: specifically, capacity divestiture will not necessarily imply lower market prices.

Trade in bilateral oligopoly with endogenous market formation

We study a strategic market game in which traders are endowed with both a good and money and can choose whether to buy or sell the good. We derive conditions under which a non-autarkic equilibrium exists and when the only equilibrium is autarky. Autarky is ‘nice’ (robust to small perturbations in the game) when it is the only equilibrium, and ‘very nice’ (robust to large perturbations) when no gains from trade exist. We characterize economies where autarky is nice but not very nice; that is, when gains from trade exist and yet no trade takes place

Network Cournot Competition

Cournot competition is a fundamental economic model that represents firms competing in a single market of a homogeneous good. Each firm tries to maximize its utility---a function of the production cost as well as market price of the product---by deciding on the amount of production. In today's dynamic and diverse economy, many firms often compete in more than one market simultaneously, i.e., each market might be shared among a subset of these firms. In this situation, a bipartite graph models the access restriction where firms are on one side, markets are on the other side, and edges demonstrate whether a firm has access to a market or not. We call this game \emph{Network Cournot Competition} (NCC). In this paper, we propose algorithms for finding pure Nash equilibria of NCC games in different situations. First, we carefully design a potential function for NCC, when the price functions for markets are linear functions of the production in that market. However, for nonlinear price functions, this approach is not feasible. We model the problem as a nonlinear complementarity problem in this case, and design a polynomial-time algorithm that finds an equilibrium of the game for strongly convex cost functions and strongly monotone revenue functions. We also explore the class of price functions that ensures strong monotonicity of the revenue function, and show it consists of a broad class of functions. Moreover, we discuss the uniqueness of equilibria in both of these cases which means our algorithms find the unique equilibria of the games. Last but not least, when the cost of production in one market is independent from the cost of production in other markets for all firms, the problem can be separated into several independent classical \emph{Cournot Oligopoly} problems. We give the first combinatorial algorithm for this widely studied problem

Uniqueness of Coalitional Equilibria

We provide an existence and a uniqueness result for coalitional equilibria of a game in strategic form. Both results are illustrated for a public good game and a homogeneous Cournot-oligopoly game.Existence and uniqueness of coalitional equilibrium, Game in strategic form

A test of collusive behavior based on incentives

This paper proposes a novel collusion test based on the analysis of incentives faced by each firm in a colluding coalition. In fact, once collusion is in effect, each colluding firm faces the incentive to secretly deviate from the agreement, since it thereby increases its profits, although the colluding firms’ joint profit decreases. Thus, in a colluding coalition each firm has marginal revenues, calculated with Nash conjectures, which are larger than its marginal costs. The collusion test is based on the rejection of the null hypothesis that the firm marginal revenues with Nash conjectures are equal to or less than its marginal costs.info:eu-repo/semantics/publishedVersio