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短期内急剧下降。虽然外国供应商主导了日本市场，但由于自1960年代以来进行了大量的重新种植，在过去十年中，成熟的国内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变化将影响世界市场和木材贸易。该项目为日本提供了一个林业部门模式。模型由三部分组成：第一部分是利用1973 - 1991年的年度数据建立的日美加三国木材贸易模型。该模型的第二部分是区域木材市场模型，使用日本区域木材市场的汇总数据。最后一部分是日本市场的空间和时间木材分配模型，这一部分提供了一个区域分配，并建立了市场的空间均衡。以北美地区的木材采伐水平为例，通过实验分析，发现东北地区和中国地区在向关东木材市场运送木材方面存在竞争。至于九州地区，运输成本如此之高，供应过剩仍然存在。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，虽然运输成本是木材供应商总成本的重要组成部分，但其他成本，如采伐成本和工资，可能在区分其产品与市场上的其他产品方面发挥重要作用。必须进行进一步的研究，以将其他费用应用到拟议的模式中。

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.