OPTIMUM-WELFARE AND MAXIMUM-REVENUE TARIFFS UNDER BERTRAND DUOPOLY

This article derives the maximum‐revenue tariff and the optimum‐welfare tariff under Bertrand duopoly with differentiated products. It is shown that both tariffs are lower under Bertrand duopoly than under Cournot duopoly. Also, the optimum‐welfare tariff may exceed the maximum‐revenue tariff under both Bertrand duopoly and Cournot duopoly. This result is more likely the lower the costs of the home firm relative to the costs of the foreign firm, and the greater the degree of product substitutability. Also, it is shown that the optimum‐welfare tariff is less likely to exceed the maximum‐revenue tariff under Bertrand duopoly than under Cournot duopoly.     

Product differentiation and the gains from trade under Bertrand duopoly

Abstract.  In the literature on the welfare effects of free trade under imperfect competition, one important case seems to have been overlooked, and that is the Bertrand duopoly model with differentiated products. Although many authors have analysed the welfare effects of free trade under Cournot duopoly and demonstrated the possibility of losses from trade, there has been no thorough analysis of the welfare effects of free trade under Bertrand duopoly. In this article we present a thorough analysis of the welfare effects of free trade under Bertrand duopoly with differentiated products, and it is shown that there are always gains from trade. JEL Classification: F12     

Innovation,licensing, and price vs. quantity competition

In this paper, we develop a differentiated duopoly model with endogenous cost-reducing R&D and review the argument on welfare effect of price and quantity competition in the presence of technology licensing. We show that, with licensing, the standard conclusion on duopoly (Singh and Vives, 1984) is completely reversed. Cournot competition induces lower R&D investment than Bertrand competition does. Moreover, Cournot competition leads to lower prices, lower industry profit, higher consumer surplus and higher social welfare than Bertrand competition.     

Dynamic efficiency of Cournot and Bertrand competition: input versus output spillovers

We consider the efficiency of Cournot and Bertrand equilibria in a duopoly with substitutable goods where firms invest in process R&D that generates input spillovers. Under Cournot competition firms always invest more in R&D than under Bertrand competition. More importantly, Cournot competition yields lower prices than Bertrand competition when the R&D production process is efficient, when spillovers are substantial, and when goods are not too differentiated. The range of cases for which total surplus under Cournot competition exceeds that under Bertrand competition is even larger as competition over quantities always yields the largest producers’ surplus.     

Price and quantity competition under free entry

This paper complements that of Cellini et al. (Cellini, R., Lambertini, L., Ottaviano, G. I. P., 2004. Welfare in a differentiated oligopoly with free entry: A cautionary note. Research in Economics, 58:125–33.), which shows that Cournot competition may generate higher welfare compared to Bertrand competition in an economy with free entry. Unlike them, we provide a more general proof for this result and show that Cournot competition generates higher welfare compared to Bertrand competition when the products are sufficiently differentiated. If the products are close substitutes, welfare is higher under Bertrand competition. We show that these qualitative results hold whether or not number of varieties increases market size. We also show when the active firms earn higher profits under Bertrand competition compared to Cournot competition.     

MFN vs Tariff Discrimination in the Presence of Cross Ownership

We develop a three‐country two‐firm model to examine the superiority of most favored nation (MFN) vs tariff discrimination in global welfare by taking into account the cross ownership between exporters. We obtain several interesting results as follows. First, given cross ownership of financial interests and linear demand, the government of the importing country will impose a lower (higher) tariff on the low‐cost (high‐cost) firm and the global welfare under tariff discrimination will be higher than that under MFN, regardless of whether the mode of competition is Cournot or Bertrand competition, when the magnitude of cross ownership is relatively large compared with the cost difference. Second, given the cross ownership of corporate control and linear demand, the global welfare under tariff discrimination will be identical to that under MFN.     

Information sharing about a demand shock

This paper examines two questions in asymmetric Cournot and Bertrand oligopoly with a demand shock. Under which conditions is information sharing a subgame-perfect equilibrium? What is the welfare effect when firms are better off? Given these questions, the normal assumptions in the earlier literature can be relaxed in three ways: demand functions can be asymmetric; a demand shock can affect firms differently; distributions of the demand shock and information signals can be arbitrary. Under these general assumptions, the answer to the first question is: every firm's response to the demand shock is stronger when all firms have perfect information than when one firm does so alone; the answer to the second question is: social welfare increases in Cournot competition, and consumer surplus decreases in Bertrand competition.     

Collusion in Differentiated Duopolies with Quadratic Costs

The analysis of collusion in infinitely repeated duopoly games has generally assumed that marginal cost is constant, but this note uses quadratic costs (linear marginal costs) to compare the sustainability of collusion under Bertrand and Cournot duopoly with differentiated products. It is shown that when marginal costs are sufficiently increasing in output, then it is always easier to sustain collusion under Cournot duopoly than under Bertrand duopoly for any degree of product substitutability.     

Licensing under vertical product differentiation: Price vs. quantity competition

This paper develops a duopoly model of vertical product differentiation where two domestic firms incur variable costs of quality development. These domestic firms can purchase a superior foreign technology through licensing. Outcomes between Bertrand and Cournot competition are compared. We find that licensing raises domestic welfare, and domestic welfare is higher in Bertrand than in Cournot competition regardless of whether or not domestic firms engage in licensing. Non-exclusive licensing is also found to benefit the domestic country more than exclusive licensing.     

PRICE AND QUANTITY COMPETITION IN A UNIONISED MIXED DUOPOLY: THE CASES OF SUBSTITUTES AND COMPLEMENTS*

We investigate a differentiated mixed duopoly in which private and public firms can choose to strategically set prices or quantities when unions are present. For the case of a unionised mixed duopoly, there exists a dominant strategy only for the public firm that chooses Bertrand competition irrespective of whether the goods are substitutes or complements; there is no dominant strategy for a private firm. Thus, we show that regardless of the nature of goods, social welfare under Bertrand competition is always determined in equilibrium, wherein Bertrand competition entails higher social welfare than Cournot competition. Moreover, our main results hold irrespective of the nature of goods, with the exception that when a sufficiently large parameter of complements is employed, the ranking of a private firm's profit is not reversed, which is in contrast to the standard findings.     

Emission tax and optimal privatization in Cournot–Bertrand comparison

We compare a Cournot with a Bertrand duopoly in a differentiated mixed market when both emission tax and privatization policies are used together. We find that the optimal emission tax is always lower than the marginal environmental damage, and it is always lower under Cournot than under Bertrand. We also find that the optimal privatization is always a partial privatization, and it is always higher under Cournot than under Bertrand. The socially optimal combinations of emission tax and privatization will damage the environment most, but Cournot yields lower environmental damage and social welfare than those under Bertrand. Finally, we show that the environmental damage is non-monotone in the level of privatization under both Cournot and Bertrand competitions.     

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 versus Cournot competition in a downstream mixed oligopoly with foreign ownership

Focusing on foreign ownership in the private firm, we examine the Cournot-Bertrand comparison in a mixed oligopolistic market with vertical market structure. We have found that if public and private firms were charged with uniform price for their inputs, then Cournot-Bertrand ranking in market outcomes confirms those obtained by Ghosh and Mitra (2010). This implies that under uniform pricing in the upstream sector, the vertical market structure does not have substantial influences on Cournot-Bertrand ranking. However, if discriminatory pricing is adopted, firm's profits, output, and social welfare are often reversed to those obtained from uniform pricing in the upstream sector. Given the closeness of products, if the share of foreign ownership is sufficiently low, social welfare in Cournot competition can exceed that of Bertrand competition, contrasting with the standard welfare ranking that Bertrand welfare is strictly higher than Cournot. This implies that Cournot competition can be more socially desirable than Bertrand in mixed oligopoly with vertical market structure if discriminatory pricing scheme is adopted by foreign upstream monopolists.     

考虑港口收费管制的进出口贸易竞争研究

考虑港口的收费管制因素,建立了进出口贸易竞争模型。该模型由一个出口国和两个进口国组成,且各国都拥有一个港口,位于出口国的两家公司均向两个进口国销售商品,并在各个进口国展开市场竞争（古诺竞争或伯川德竞争）,各贸易国的港口根据其是否存在价格管制确定港口收费。针对进出口公司的每种竞争模式,得到了不同的港口收费管制组合下各贸易国的港口收费、港口利润和社会福利,并将竞争均衡结果进行了比较。研究发现： （1）在进出口公司古诺竞争模式下,若三个贸易国的港口都无收费管制（有收费管制）且进出口产品的差异较大 （小）时,各贸易国的社会福利和港口利润均更高; （2）在进出口公司伯川德竞争模式下,若进出口产品的差异较大 （小）,则出口国的港口利润主要取决于港口收费 （贸易量）,而进口国恰好相反; （3）当进出口产品的差异较大 （小）时,进出口公司在古诺 （伯川德）竞争模式下各贸易国的社会福利、港口利润以及港口使用费都更高。     

POLITICAL ECONOMY OF STRATEGIC EXPORT POLICY IN A DIFFERENTIATED DUOPOLY*

This paper investigates the effect of a home firm's lobbying on a strategic export policy in a third market with a differentiated duopoly. We focus on its effect on domestic welfare under Bertrand and Cournot competition. Regardless of the mode of competition, the strategic export policy cannot improve domestic welfare in the presence of lobbying if the degree of product differentiation is high or the government is overly concerned with political contribution relative to domestic welfare. Moreover, for the same degree of product differentiation, the lobbying‐induced export policy is more likely to deteriorate domestic welfare relative to free trade under Cournot competition.     

The Bertrand Paradox,the Useless Auctioneer and the Launhardt Model

We revisit the Cournot–Bertrand debate in the light of Cournot, Edgeworth and Launhardt, tracing back to Launhardt the origin of price competition in duopoly models with constant returns to scale. Then, we discuss the formalisation of consumer utility function for differentiated products, first appearing in Launhardt and then in Bowley. This allows us to point out that assuming that firms know the demand function(s) is equivalent to assuming that they know the structure of consumer preferences. Therefore, we argue that there is no role for the auctioneer, either in Cournot or in Walras.     

A Note on Strategic Trade Policy and Endogenous Quality Choice*

This paper shows that some of the main policy implications in Park (2001 ) and Zhou, Spencer, and Vertinsky (2002 ) are sensitive to their assumptions on marginal production costs. The unilaterally optimal policy for investment towards quality improvement is analyzed, assuming constant and non‐negative marginal production costs under vertically differentiated international duopoly. If marginal production costs are different across firms, the optimal policy for each exporting country may be opposite in its sign from that shown by the existing papers under Bertrand competition. The policy reversal may also occur for the low‐quality exporting country under Cournot competition.     

OPTIMUM-WELFARE AND MAXIMUM-REVENUE TARIFFS IN MIXED OLIGOPOLY WITH FOREIGN COMPETITORS

This paper re-examines the important tariff ranking issue under a linear mixed oligopoly model with foreign competitors and asymmetric costs. We demonstrate that under Cournot competition, when the size of domestic private and foreign private firms become more unequally distributed, optimum-welfare tariff will exceed maximum-revenue tariff. We also show that under Stackelberg competition, when the domestic government protects its domestic sector, it will levy higher optimum-welfare tariffs versus maximum-revenue tariffs; however, when it decides to open its doors more for foreign competitors, it will need to levy higher maximum-revenue tariffs versus optimum-welfare tariffs. The above results remain valid whether the domestic public firm acts as a leader or a follower.     

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.     

Domestic entry, optimum-welfare and maximum-revenue tariffs

In this paper, we examine the ranking of the maximum-revenue tariff and the optimum-welfare tariff under a linear Cournot oligopoly model without and with free entry of domestic firms. We demonstrate that in a regulated entry oligopoly with asymmetric costs, when the marginal cost of the domestic firms exceeds a critical value, the maximum-revenue tariff is higher than the optimum-welfare tariff. We then show that under free entry of domestic firms with asymmetric costs, when the fixed cost gets larger and the domestic firms become fewer, the difference between the optimum-welfare tariff and the maximum-revenue tariff becomes larger.