Faculty of Economics, Toyo University, Tokyo, Japan.
Department of Economics, Seinan Gakuin University, Fukuoka, Japan.
PLoS One. 2022 Sep 9;17(9):e0273904. doi: 10.1371/journal.pone.0273904. eCollection 2022.
In this article, we construct an international oligopoly that explicitly incorporates transporter behavior. In each country, there is one firm that produces differentiated goods and invests in product-differentiating R&D and one transporter that transports the differentiated goods. We adopt a three-stage game in which the firms decide their R&D investment level to determine the degree of horizontal differentiation, the transporters determine the transportation prices through Cournot competition, and then the firms determine the quantities of production. We find that an increase in R&D efficiency in the product differentiation of firms leads to a decrease in transportation prices. We also reveal that an increase in the efficiency of product differentiation always reduces the profits of firms. These results explain the empirically plausible long-term trend of declining transportation prices and also provide a counterintuitive implication that efficiency gains reduce the degree of product differentiation.
在本文中，我们构建了一个明确纳入转运商行为的国际寡头垄断模型。在每个国家中，都有一家生产差异化产品并投资于产品差异化研发的企业，以及一家运输差异化产品的转运商。我们采用了三阶段博弈，其中企业决定其研发投资水平以确定水平差异化程度，转运商通过古诺竞争确定运输价格，然后企业确定产量。我们发现，企业产品差异化研发效率的提高会导致运输价格的下降。我们还揭示了产品差异化效率的提高总是会降低企业的利润。这些结果解释了运输价格长期下降的经验上合理的趋势，也提供了一个反直觉的含义，即效率提高会降低产品差异化程度。
