Bertrand versus Cournot revisited

Summary. Bertrand criticized Cournot's analysis of the competitive process, arguing that firms should be seen as playing a strategy of setting price below competitors' prices (henceforth, the Bertrand strategy) instead of a strategy of accepting the price needed to sell an optimal quantity (the Cournot strategy). We characterize Nash equilibria in a generalized model in which firms choose among Cournot and Bertrand strategies. Best responses always exist in this model. For the duopoly case, we show that iterated best responses converge under mild assumptions on initial states either to Cournot equilibrium or to an equilibrium in which only one firm plays the Bertrand strategy with price equal to marginal cost and that firm has zero sales. Received: December 11, 1995; revised version October 2, 1996     

Comparing Cournot and Bertrand equilibria in an asymmetric duopoly with product R&D

We compare the Cournot and Bertrand equilibria in an asymmetric duopoly with product R&D competition. If a firm’s marginal cost is lower than that of its rival, then this firm (its rival) is referred to as the more (less) efficient firm. Under each mode of competition, there are three types of equilibria: blockaded-entry, deterred-entry, and accommodated-entry. Moreover, the presence of R&D investment makes it harder for the less efficient firm to survive. Cournot competition entails a unique equilibrium, whereas Bertrand competition may yield two equilibria. It is harder for the less efficient firm to survive under Bertrand competition than under Cournot competition. Versus Cournot competition, Bertrand competition yields higher industry output, and it shifts production from the less efficient firm to the more efficient firm. This result, together with the known size effect, explains the following three findings. First, the more efficient firm has a normal output ranking, whereas the less efficient firm may demonstrate an output reversal. Second, the more efficient firm may demonstrate a R&D reversal, whereas the less efficient firm has a normal R&D ranking (its Cournot R&D effort exceeds its Bertrand R&D effort). Third, Bertrand competition is more welfare-efficient than Cournot competition.     

The Cournot-Bertrand profit differential: A reversal result in a differentiated duopoly with wage bargaining

This paper compares Cournot and Bertrand equilibria in a downstream differentiated duopoly in which the input price (wage) paid by each downstream firm is the outcome of a strategic bargain with its upstream supplier (labor union). We show that the standard result that Cournot equilibrium profits exceed those under Bertrand competition - when the differentiated duopoly game is played in imperfect substitutes - is reversible. Whether equilibrium profits are higher under Cournot or Bertrand competition is shown to depend upon the nature of the upstream agents’ preferences and on the distribution of bargaining power over the input price. We find that the standard result holds unless unions are both powerful and place considerable weight on the wage argument in their utility function.     

Bertrand competition when firms hold passive ownership stakes in one another

We show that the Bertrand oligopoly model with cost asymmetries may admit multiple Nash equilibria when firms hold passive ownership stakes in each other. The equilibrium price may be as high as the monopoly price of the most efficient firm.     

Asymmetric equilibria under price cap regulation

This study analyzes the effects of a price-cap regulation on market outcomes in Cournot and Stackelberg duopolies. Although two firms are ex-ante identical, there are asymmetric Cournot equilibria as well as the symmetric equilibrium under the price-cap regulation, when the price-cap level is binding. By contrast, the Stackelberg equilibrium is unique and equivalent to the most asymmetric Cournot equilibrium under a binding price-cap level. We present several comparative statics results with respect to the equilibrium outcomes. The main concern of this study is the welfare effect of a change in a price-cap level. We show that when asymmetric Cournot equilibria or the Stackelberg equilibrium are focused on, a reduction in a price-cap level may be socially harmful even if the price-cap level is more than the competitive price.     

On the comparison of price and quantity competition under endogenous timing

This paper compares Bertrand and Cournot equilibria in a differentiated duopoly with linear demand, and asymmetric constant marginal cost under endogenous timing. It shows that endogenous timing leads to two sequential play with both leader–follower configurations in Bertrand, but simultaneous play in Cournot. Moreover, every firm’s mark-up/output ratio and the two firms’ weighted ‘average’ price are all lower, but the two firms’ weighted ‘average’ output is higher in either of the two sequential Bertrand equilibria than in the simultaneous-move Cournot equilibrium.     

Nature of Competition and New Technology Adoption

The incentives to adopt cost‐reducing technology by firms in a horizontally‐differentiated duopoly are analysed in the present paper. Cost reduction depends on the ‘quality’ of the ‘new technology’. A firm has to procure such technology in a ‘scoring auction’. When the quality offered by the suppliers of this technology lies in the interior of the feasible range, both firms adopt the new technology regardless of the nature of competition (Cournot or Bertrand). However, when there is a corner solution, there are equilibria where only one firm (or no firm) adopts the new technology. With a corner solution the nature of competition affects the equilibrium outcomes.     

On the endogeneity of Cournot-Nash and Stackelberg equilibria: games of accumulation

We characterize equilibria of games with two properties: (i) Agents have the opportunity to adjust their strategic variable after their initial choices and before payoffs occur; but (ii) they can only add to their initial amounts. The equilibrium set consists of just the Cournot-Nash outcome, one or both Stackelberg outcomes, or a continuum of points including the Cournot-Nash outcome and one or both Stackelberg outcomes. A simple theorem that uses agents’ standard one-period reaction functions and the one-period Cournot-Nash and Stackelberg equilibria delineates the equilibrium set. Applications include contribution, oligopoly, and rent-seeking games.     

ENDOGENOUS TIMING IN QUALITY CHOICES AND PRICE COMPETITION

We modify the price‐setting version of the vertically differentiated duopoly model by Aoki (2003) by introducing an extended game in which firms noncooperatively choose the timing of moves at the quality stage. Our results show that there are multiple equilibria in pure strategies, whereby firms always select sequential play at the quality stage. We also investigate the mixed‐strategy equilibrium, revealing that the probability of generating outcomes out of equilibrium is higher than the probability of playing one Nash equilibria in pure strategies. In the alternative case with full market coverage, we show that the quality stage is solved in dominant strategies and therefore the choice of roles becomes irrelevant as the Nash and Stackelberg solutions coincide. With full market coverage and corner solution, the results show that the game has a unique subgame perfect equilibrium in pure strategies, where the high‐quality firm takes the lead in the quality stage.     

Multinational Corporations, Stackelberg Leadership, and Tariff-jumping

In this paper we consider the traditional entry mode choice of an incumbent monopolist facing entry by a single foreign firm. By allowing entry to be either via exporting or foreign direct investment and for the possibility of Stackelberg equilibria where firms can set quantities in one of two time periods, namely “early” or “late,” we find conditions where both Cournot and Stackelberg equilibria emerge endogenously. Furthermore, by introducing a simple linear tariff, we see that it not only affects the choice of exporting and FDI in a nonlinear way, but that it can also affect the type of equilibrium that emerges.     

ENDOGENOUS TIMING AND STRATEGIC CHOICE: THE COURNOT‐BERTRAND MODEL

Cournot establishes a Nash equilibrium to a duopoly game under output competition; Bertrand finds a different Nash equilibrium under price competition. Both treat the strategic choice variable (output versus price) and the timing of play as exogenous. We investigate Cournot‐Bertrand models where one firm competes in output and the other competes in price in both static and dynamic settings. We also develop a general model where both the timing of play and the strategic choice variables are endogenous. Consistent with the conduct of Honda and Scion, we show that Cournot‐Bertrand behaviour can be a Nash equilibrium outcome.     

Firm Scale and the Endogenous Timing of Entry: a Choice between Commitment and Flexibility

This paper presents a model of stochastic oligopoly with demand uncertainty where firms endogenously choose entry timing. We examine two extreme types of market structure and show that the equilibrium correspondence that connects them is continous. With two identically sized firms, there are symmetric, Cournot type equilibria where the probability of early entry declines with greater uncertainty, and for low uncertainty two asymmetric equilibria. With one large firm with a continuum of nonatomic firms, there is a unique Stackelberg equilibrium. We conclude that the behavior of a dominant firm with a finite fringe can be approximated by Stackelberg equilibrium.Journal of Economic LiteratureClassification Numbers?: D21, L11.     

COMPETITION FOR MARKET SHARE OR FOR MARKET SIZE: OLIGOPOLISTIC EQUILIBRIA WITH VARYING COMPETITIVE TOUGHNESS*

For an industry producing a composite commodity, we propose a comprehensive concept of oligopolistic equilibrium, allowing for a parameterized continuum of regimes varying in competitive toughness. Each firm sets simultaneously its price and its quantity under two constraints, relative to its market share and to market size. The price and the quantity equilibrium outcomes always belong to the set of oligopolistic equilibria. When firms are identical and we let their number increase, any sequence of symmetric oligopolistic equilibria converges to the monopolistic competition outcome. Further results are derived in the symmetric CES case, concerning in particular the collusive solution enforceability.     

Strategic Choice of Quantity Stickiness and Stackelberg Leadership

This paper re‐examines endogenous Stackelberg leader–follower relations by modelling an explicitly dynamic market. We analyze a twice‐repeated duopoly where, in the beginning, each firm chooses either a quantity‐sticky production mode or a quantity‐flexible production mode. The size of the market becomes observable after the first period. In the second period, a firm can adjust its quantity if and only if it has adopted the flexible mode. Hence, if one firm chooses the sticky mode whilst the other chooses the flexible mode, then they respectively play the roles of a Stackelberg leader and a Stackelberg follower in the second marketing period. Somewhat intriguing is the finding that such a Stackelberg‐like equilibrium can arise only when the relative weight of the pre‐Stackelberg first marketing period is sufficiently high, with time preferences being sufficiently strong.     

Diagrammatic Demonstration of the Cournot Equilibrium

This note further develops Ikema's (1990, 1991) diagrammatic demonstrati on of the Cournot-oligopoly equilibrium on the price- quantity plane. It is shown that Ikema's method can be used to illustrate the Stackelberg and Bertrand equilibria on the price- quantity plane. Furthermore, we algebraically derive the ``monopoly- equilibrium' curve and show that the Cournot- oligopoly equilibrium is stable if the monopoly-equilibrium curves for all producers are upward sloping.     

INTEGER PRICING AND BERTRAND-EDGEWORTH OLIGOPOLY WITH STRICTLY CONVEX COSTS: IS IT WORTH MORE THAN A PENNY?

In this paper we analyse the implications of integer pricing for Bertrand Edgeworth oligopoly with strictly convex costs. When price is a continuous variable, there is a generic non-existence of pure-strategy equilibrium. In the case of integer pricing, this is not so. We characterize a set of possible single price equilibria around the competitive price, which if non-empty will constitute the set of single price equilibria if the industry is large enough. Furthermore, we provide an example in which the highest equilibrium price can be arbitrarily far from the competitive price.     

MARKET PRICE MECHANISMS AND STACKELBERG GENERAL EQUILIBRIA: AN EXAMPLE

This paper considers Stackelberg competition in a general equilibrium framework with a productive sector. The working of market power and the configurations of strategic interactions are complexified by the presence of a leader. Two market price mechanisms are studied: one is associated with the Stackelberg–Walras equilibrium and the other is linked to the Stackelberg–Cournot equilibrium. Throughout the example of a two commodity economy, several results are obtained about equilibria mergings and about welfare comparisons.     

Price and Quantity Competition in a Differentiated Duopoly With Network Compatibility Effects

We consider the efficiency of price and quantity competition in a network products market, where we observe product compatibility with network externalities (hereafter, network compatibility effects). In particular, if network compatibility effects between firms are sufficiently asymmetric, the Cournot equilibrium is more efficient than the Bertrand equilibrium in terms of larger consumer, producer and total surpluses. Then, we consider an endogenous choice of the strategic variables, price and quantity. If the degree of network compatibility effects of the rival firm is larger (smaller) than the degree of product substitutability, then choosing prices (quantities) is a dominant strategy for the firm. Thus, if the network compatibility effects of both firms are larger (smaller), the Bertrand (Cournot) equilibrium arises. Furthermore, if the network compatibility effects between the firms are sufficiently asymmetric, the firm with a larger (smaller) network compatibility effect than a certain level of product substitutability chooses quantities (prices). In this case, the Cournot–Bertrand equilibrium arises, which is less (more) efficient than the Cournot equilibrium in terms of consumer (producer) surplus.     

BERTRAND Vs. COURNOT COMPETITION WITH UPSTREAM FIRM INVESTMENT

This paper compares Bertrand and Cournot competition in a vertical structure in which the upstream firm sets the input price and makes R&D investments. We show that from the downstream firms’ point of view, Cournot competition has the advantage of a more monopolistic effect, leading to the setting of a higher price, but has the disadvantage of inducing a lower incentive for the upstream firm to invest. On the other hand, Bertrand competition has the advantage of providing a greater incentive for the upstream firm to invest but has the disadvantage of a more competitive effect, leading to the setting of a lower price. Our main findings are as follows. First, R&D investment level is greater under Bertrand competition than under Cournot competition. Second, from the standpoint of the upstream firm and industry, Bertrand competition is more efficient than Cournot competition. Third, from the standpoint of the downstream firms, Bertrand competition is more efficient than Cournot when investment is sufficiently efficient and products are sufficiently differentiated.     

FIRM SIZE AND PRICING POLICY

We relate pricing policy of firms to their size, where firm size is interpreted as the size of the clientele served by the concerned firm. We argue that a firm with a large clientele faces a more severe reputational backlash if it ‘reneges’, i.e., deviates from its earlier price offer. This allows the firm to effectively commit to its offers, leading to a unique equilibrium without delay. Interestingly, this equilibrium corresponds to the equilibrium of the related model that does not allow for reneging possibilities. For smaller firms, however, the reputational effects are much less intense, and consequently the equilibria may involve deviation possibilities. In this case, the equilibria are non‐unique and may involve delays as well.