Market Structure, Scale Economies and Industry Performance

We provide an extensive and general investigation of the effects on industry performance (profits and social welfare) of exogenously changing the number of firms in a Cournot framework. This amounts to an in-depth exploration of the well-known trade-off between competition and production efficiency. We establish that under scale economies, welfare is maximized by a finite number of firms. Our results shed light on several theoretical issues and policy debates in industrial organization, including the relationship between the Herfindahl index and social welfare, free versus socially optimal entry, concentration and profitability, destructive competition and natural monopoly. Our analytical approach combines simplicity with generalityCournot oligopoly; Returns to scale; Entry; Equilibrium comparative statics

On Zermelo's theorem

A famous result in game theory known as Zermelo's theorem says that "in chess either White can force a win, or Black can force a win, or both sides can force at least a draw". The present paper extends this result to the class of all finite-stage two-player games of complete information with alternating moves. It is shown that in any such game either the first player has a winning strategy, or the second player has a winning strategy, or both have unbeatable strategies

Information Structure and the Tragedy of the Commons in Resource Extraction

This paper considers the well-known Levhari-Mirman model of resource extraction, and investigates the effects of the information structure of the dynamic game - open-loop, Markovian or history-dependent - on the equilibrium consumption path and the overall utility of the agents. The open-loop regime yields a Pareto-optimal outcome. The Markovian regime leads to the most pronounced version of the tragedy of the commons. History-dependent behavior yields an outcome set that is intermediate between the other two cases.Dynamic resource games; Open-loop; Closed-loop and trigger strategies; Pareto optimality, Regulation

First and Second Mover Advantage in Asymmetric Price Duopoly

We consider the issue of first versus second mover advantage in differentiated-product Bertrand duopoly with asymmetric linear costs. We provide a generalization of some well-known results in the cases where prices are strategic substitutes or complements, dispensing with extraneous assumptions of single-valued optimal reactions, uniqueness of Bertrand equilibrium, ... We also consider a new mixed case. Our approach is based on the theory of supermodular optimization/games. Furthermore, we show that even when prices are strategic complemnts, one firm may have a first mover advantage under a linear demand.

Ranking economics departments worldwide on the basis of PhD placement

An objective ranking of economics departments worldwide in terms of graduate education is derived. The central idea is that the value of a department is the sum of the values of its PhD graduates, as reflected in the values of their current employing departments. The scores are thus derived as solutions to a linear system of simultaneous equations in the values. The sample includes the top fifty-four departments, the composition of which is determined endogenously using a criterion requiring a minimum of four placements in the departments comprising the sample. Two other related rankings are proposed, which place more emphasis on more recent faculty recruitments. The results point to a very high concentration in the economics PhD education market worldwide, confirming the dominance of the top U.S. departments, in particular of Harvard and M.I.T. Nevertheless, a modest de-concentration trend is under way. The rankings are in close agreement with the 1994 National Research Council survey ranking based on the perceived quality of PhD programsEconomics PhD education; scientific evaluation methods; economic department ranking

Endogenous timing in a mixed duopoly

This paper addresses the issue of endogenizing the equilibrium solution when a private - domestic or foreign - firm competes in the quantities with a public, welfare maximizing firm. Theoretical literature on mixed oligopolies, in fact, provides results and policy implications that crucially rely on the notion of equilibrium assumed, either sequential or simultaneous. In the framework of the endogenous timing model of Hamilton and Slutsky (1990), we show that simultaneous play never emerges as the equilibrium of mixed duopoly games. We provide sufficient conditions for the emergence of public and/or private leadership equilibria. These results are in sharp contrast with those obtained in private duopoly games in which simultaneous play is the general result. We show that the key difference lies in the fact that the objective of a welfare maximizing firm is generally increasing in the rival's output, while the contrary holds for private firms. We develop a comprehensive analysis of a mixed duopoly considering both the cases of domestic and international competition, and the possible strategic complementarity and substitutability. From a methodological viewpoint we make large use of the basic results of the theory of supermodular games in order to avoid extraneous assumptions such as concavity, existence and uniqueness of the equilibria

Network effects, market structure and industry performance

This paper provides a thorough analysis of oligopolistic markets with positive demand-side network externalities and perfect compatibility. The minimal structure imposed on the model primitives is such that industry output increases in a firm's rivals' total output as well as in the expected network size. This leads to a generalized equilibrium existence treatment that includes guarantees for a nontrivial equilibrium, and some insight into possible multiplicity of equilibria. We formalize the concept of industry viability and show that is it always enhanced by having more firms in the market and/or by technological improvements. We also characterize the effects of market structure on industry performance, with an emphasis on departures from standard markets. The approach relies on latticetheoretic methods, which allow for a unified treatment of various general results in the literature on network goods. Several illustrative examples with closed-form solutions are also provided. --Network effects,demand-side externalities,monotone comparative statics,Cournot oligopoly,supermodularity

Sequential Games of Resource Extraction: Existence of Nash Equilibria

A general model for noncooperative extraction of common-property resource is considered. The main result is that this sequential game has a Nash equilibrium in stationary strategies. The proof is based on an infinite dimensional fixed-point theorem, and relies crucially on the topology of epi-convergence. A byproduct of the analysis is that Nash equilibrium strategies may be selected such that marginal propensities of consumption are bounded above by one

Market structure, scale economies, and industry performance

"We provide an extensive and general investigation of the effects on industry performance (profits and social welfare) of exogenously changing the number of firms in a Cournot framework. This amounts to an in-depth exploration of the well-known trade-off between competition and production efficiency. We establish that under scale economies, welfare is maximized by a finite number of firms. Our results shed light on several theoretical issues and policy debates in industrial organization, including the relationship between the Herfindahl index and social welfare, free versus socially optimal entry, concentration and profitability, destructive competition and natural monopoly. Our analytical approach combines simplicity with generality." (author's abstract)"In dem Beitrag wird im Rahmen eines Cournot-Ansatzes eine allgemeine Untersuchung der Auswirkungen der exogen sich ändernden Anzahl von Unternehmen auf das Marktergebnis (Gewinne und soziale Wohlfahrt) vorgestellt. Dabei wird in einer analytischen Betrachtung das bekannte Trade-off zwischen Wettbewerb und Produktionseffizienz herausgearbeitet. Es wird gezeigt, daß beim Vorliegen von Größenvorteilen die Wohlfahrt durch eine endliche Zahl von Firmen maximiert wird. Das Ergebnis beleuchtet verschiedene Aspekte der wirtschaftstheoretischen und industriepolitischen Diskussion, einschließlich der Beziehungen zwischen den Herfindahl-Index und der sozialen Wohlfahrt, freiem versus sozial optimalem Markteintritt, Konzentration und Profitabilität, ruinösem Wettbewerb und natürlichem Monopol. Der analytische Ansatz vereint Einfachheit mit Allgemeinheit." (Autorenreferat

A Characterization of Globally Optimal Paths in the Non-Classical Growth Model

We show that the monotonicity property of optimal paths (or, equivalently, the uniform boundedness of the marginal propensity of consumption by unity) is a necessary condition for local (as well as for global) optimality, and is also sufficient for local optimality, but not for global optimality. We also show that the well-known properties of the value function — continuity and monotonicity — are sufficient (along with the above conditions) to guarantee global optimality. In other words, if at any stock level, a local non-global maximizer is selected, a discontinuity in the value function will be observed. We suggest that the previous literature on this problem has not distinguished between local and global maxima, and consequently has not attempted to derive conditions that uniquely characterize global optimality. This is the major aim of this paper, and we hope to have provided some insight towards a systematic approach to non-convex dynamic optimization