Simulation analysis of timber trade structure among japan, the U.S.and Canada influenced by conservation problems.

日本木材市场高度依赖外国供应商。由于世界范围内的环境保护努力，出口到日本的外国原木和木材的数量可能在近期急剧下降。虽然外国供应商在日本市场占主导地位，但由于1960年代以来进行了大量的重新种植，过去十年来国内成熟森林的面积和数量都有所增加。由于日本木材市场在世界木材市场中占有重要地位，作为最大的木材进口国，日本国内木材采伐水平的未来变化将影响世界市场和木材贸易。该项目为日本的林业部门提供了一个模式。该模型由三部分组成：第一部分是日本、美国和加拿大之间的木材贸易模型，使用的是1973年至1991年的年度数据。该模型的第二部分是区域木材市场模型，使用来自日本区域木材市场的汇总数据。第四部分是日本木材市场的时空配置模型；这一组成部分提供了区域分配，并在市场中建立了空间均衡。使用北美木材采伐水平的几种情景，我们的实验分析表明，东北地区和中国地区相互竞争，将木材运往关东木材市场。至于九州地区，由于运输成本太高，供应仍然过剩。这与我们的观察结果不一致，我们的观察结果显示，大量木材从九州地区运往关东地区。这意味着，虽然运输费用是木材供应商总费用的一个重要部分，但其他费用，例如采伐费用和工资，可能在使其产品在市场上有别于其他产品方面发挥重要作用。必须进行进一步的研究，以将其他成本应用到拟议的模型中。

Japanese timber markets are highly dependent on foreign suppliers. The volume of foreign logs and lumber exported to Japan may decline drastically in the near term, as a result of worldwide environmental preservation efforts. Although foreign suppliers dominate the Japanese market, the area and volume of mature, domestic forests increased during the last decade as a result of the large amount of replanting done since the 1960s. Because the Japanese timber market plays an important role in world timber markets, as the largest timber importer, prospective changes in Japanese domestic timber harvest level will affect world markets and timber trade. This project presents a forest sector model for Japan. The model consists of three parts : the first part is a model of timber trade among Japan, the US and Canada using annual data from 1973 to 1991. The second part of this model is a model of regional timber markets, using pooled data from regional timber markets in Japan. The last part is spatial and temporal lumber allocation model for Japanese markets ; this component provides a regional allocation, and establishes a spatial equilibrium in markets. Using several scenarios for North American timber harvest level, our experimental analysis shows that Tohoku region and Chugoku region compete each other to ship their lumber to Kanto lumber market. As for Kyushu region, transportation costs are so high that excess supply remains. This is inconsistent with our observations, which shows large shipping of lumber from Kyushu region to Kanto region. This implies that although transportation costs are an important part of the total costs for lumber suppliers, other costs, such as harvesting costs and wage, may play an important role in differentiating their products from others at the market. Further research has to be conducted to apply other costs into the proposed model.