A Spatial Equilibrium Model of International Trade with Oligopolistic Processors Included

Kawaguchi (2003) developed spatial equilibrium model by changing the traditional marketing route \u22producers-consumers\u22 to more concrete marketing route \u22producers as price takers-profit making traders-consumers\u22 . And Kubo, Kano and Maeda (2008b) revised the spatial equilibrium model by considering oligopolistic processing firms which make some processed goods from a raw material. The oligopolistic processing firms are characterized as the firm which can hold a great control over their products\u27 prices against the producers in raw material market and the consumers in processed goods market. But it is insufficient to apply the model to quantitative analysis of International trade. The purpose of this paper is to apply the model of Kubo, Kano and Maeda (2008b) to the model of International trade based on Shono and Kawaguchi (1999a, 1999b), Maeda (2001) which are the model of perfectly competitive international trade and of oligopolistic international trade. Also, analyses simulations with the use of the model are performed under the four scenarios, 1) a perfectly competitive in both raw material market and processed goods market, 2) supply-oligopolistic in processed goods market, 3) demand-oligopolistic in raw material market, 4) both supply-oligopolistic in processed goods market and demand-oligopolistic in raw material market. As a result, the following facts are yielded: oligopolistic processing firms beat the price down in raw material market and push up the price in processed goods, which are more profitable than price-takers, which are the same results as Kubo, Kano and Maeda (2008b) .以上,本稿では,庄野･川口(1999a,b),前田(2001)により展開された国際貿易空間均衡モデルに,久保ら (2008b)による複数財の寡占的加工業者を導入した.さらに,新たに展開されたモデルをもとに数値例として, 市場構造の相違が均衡解に与える影響を分析した. 数値例の結果,寡占的加工業者が原材料の需要者および加工品の供給者として市場支配力をもつ場合の均衡量は, 国際貿易における諸制度を考慮しても,久保ら(2008b)と同様の傾向をもつものであった.つまり,寡占的加工 業者による市場の均衡量は,本稿のシナリオ1,シナリオ2,シナリオ3の市場支配力を部分的もしくは完全に持 たない場合と比較して少なり,一方で,加工品市場価格と原材料市場価格の価格差は大きくなるという結果が得られた