内生水平产品差异与最优贸易政策

与以往分析政府最优贸易政策的文献通常假定产品同质或者差异程度外生给定不同,文章假定产品的水平差异内生决定,建立一个三国两厂商的三阶段博弈,探讨厂商进行Cournot数量竞争下本国政府的最优出口政策。结论发现当产品的差异程度内生决定时,提高出口课税会制造水平差异效应,降低厂商之间的竞争,提高本国利润水平,因此本国最优出口政策为征税,而不再是补贴,与以往文献不同。若产品的水平差异程度外生给定,则水平差异效果消失,本国最优贸易政策为出口补贴;并且,产品外生差异程度越高,本国政府的出口补贴率亦越高,与以往文献的分析相一致。

Optimal Trade Policy under Cournot Competitionwith Horizontal Differentiation

Using an uncovered market embedded in Hotelling’s linear city model,this paper constructs a three-country,two-firm trade model with a three-stage game to explore the unilateral optimal export policy under Cournot competition,when the degree of horizontal differentiation is endogenously determined.The paper shows that a rise in the export tax creates a horizontal differentiation effect to mitigate competition by enlarging the degree of horizontal differentiation.This leads to the result that the optimal export policy of the domestic country is to levy a tax.However the optimal policy is free trade if the two firms act as local monopolists.The optimal policy is to subsidize,if the degree of horizontal differentiation remains unchanged in the short run.Lastly,the paper shows that a rise in the degree of horizontal differentiation raises the optimal rate of subsidy.