應用賽局理論分析國際間貿易行為的競爭策略

Apply Game Theory to analyze competition strategic in the International Trade

陳永哲(Yung-Che Chen)

指導教授 ： 陳宜亨

淡江大學/商學院/產業經濟學系碩士班/碩士(2005年)

https://doi.org/10.6846/TKU.2005.00465

摘要

本文建立一個三國(第三國、本國與外國)三廠商的產品差異化的賽局模型，分析政府在貿易政策干預的前後，本國廠商與社會福利大小，假設各國各有一家廠商且皆有能力生產中間財與最終財，而中間財為要素x與要素y，其中各廠商的差異僅於成本大小不同，生產一最終財需要兩中間要素，而三國所生產的最終財皆在本國最終財市場做價格競爭。
在完全自由貿易下，就本國與外國對於要素 的需求而言，無論產品替代性大小皆為外購會比自己內製生產的利潤還要大；政府的最適貿易政策下，政府對於廠商要素 的補貼與否，端視產品替代性的大小，產品的替代性愈大，無論如何政府皆給予補貼，但如果產品的替代性很小，則政府不但不補貼，反而將會對於廠商課徵稅額；而對於第三國進行最終財課稅，將會使第三國進口的要素 價格降低，達到抑制的效果。最後無論產品替代性大小與否，政府在有貿易政策的干預，無論是廠商的利潤或是社會福利，皆會比無干預時大。
不管在產品的高替代性或是低替代性，在有政府的政策干預下，分別會使本國的廠商與社會福利達到最大，故有政府的貿易政策的干預是我們本文結論支持的重點。

關鍵字

賽局理論 ； 產品異質化 ； 寡佔 ； 國際貿易

並列摘要

This text sets up a three-country model to analyse the effects of trade policy on profits of the firms and the social welfare in the countries. Assume that each country has only one firm. Each firm has the ability to produce two kinds of intermediate inputs. With the some fixed proportion technology, each firm produce final good and play price competition in the final good market. We found that the outcomes are related to the substitution effect among the final goods produced.
Under the perfectly free trade, outsourcing can make more profit than inhouse does no matter how big the products substitutability is while under the government’s optimal trade policy, while subsidizing or tax the intermediate input productor, depend on the difference of products substitutability. If products substitutability is big, government would offer subsidy definitely, but if the substitutability of the products is very small, the government would not subsidize them but tax instead. Another finding is that levying taxes on the final good of the the other country could suppress the import element price outsourced from that country and increase home country’s welfare. No matter the difference of products substitutability is large or small, as long as government intervenes in the trade policy, the social welfare, will be bigger than dose not.

並列關鍵字

Game theory ； Product Differentiation ； Oligopoly ； International trade

參考文獻

Brander, J. A. (1981), “Intra-industry Trade in Identical Commodities,”Journal of International Economics, 11, 1-14.

Brander, J. A. and B. J. Spencer (1985), “Export Subsidies and International Market Share Rivalry,” Journal of International Economics, 18, 83-100.

Dixit, A. K. (1984), “International Trade Policy for Oligopolistic Industries,” Economic Journal, 94, Supplement, 1-16.

Chen, Y., J. Ishikawa, and Z. Yu (2004), “Trade Liberalization and Strategic Outsourcing,”Journal of International Economics , 63 , 419 – 436.

Chen, Z. and T. W. Ross (2003), “Cooperating Upstream while Competing Downstream : A Theory of Input Joint Ventures,”International Journal of Industrial Organization, 21, 381 – 397.