QUANTITATIVE ANALYSIS OF TIMBER TRADE AND FOREST PROTECTION

这项研究的重点是环境法规对日本、北美、中美洲、南美洲和大洋洲之间交易的林产品供应的影响，以寻求林产品贸易和环境保护的平衡。我们进行了林业部门分析以及林业部门建模。据透露，日本木材的价格可能不足以支付总生产成本。日本的森林培育成本几乎是主要木材出口国的五到十倍。关于林业部门建模，我们的结论是，未来的努力应：(A)开发具有多个市场层次的空间、跨期优化模型；(B)审查在跨期福利最大化形式下调整灵活性的制约因素；(C)开发能够联合模拟市场和资源模型的方法，保留其各自的细节；(D)直接接受现实世界市场/资源条件的“混乱”；(E)明确政策设想和预测中固有的不确定性。利用日本林业部门模型，我们的模拟分析表明，美国原木进口量的减少并没有对国内木材产量产生太大影响，反而加速了对日本的木材进口，这主要体现在关东。

This study has focused on impacts, resulting from environmental regulations, on forest product supply to be traded among Japan, North America, Central America, South America and Oceania to seek a balanced situation for forest products trade and environmental protection. We conducted forest sector analysis as well as forest sector modeling. It has been revealed that a price of the Japanese timber may not be high enough to cover the total production costs. Silvicultural costs in Japan are found to be almost five to ten times greater than those in the main timber exporting countries. Only considering forest resources physically, it would be possible for Japan to be self-sufficient in supplying lumber to its domestic demand.Regarding forest sector modeling, we conclude that future efforts should : (a) develop spatial, intertemporal optimization models with multiple market levels ; (b) examine constraints on adjustment flexibility in the intertemporal welfare maximization format ; (c) develop methods that allow joint simulation of market and resource models retaining their respective detail ; (d) directly embrace the "messiness" of real world market/resource conditions ; and (e) be explicit about the uncertainty inherent in policy scenarios and projections. Using the Japanese forest sector model, our simulation analysis indicates that reduction of the US log import does not have much influence on domestic lumber production, instead accelerates lumber import to Japan, which mainly can be observed in Kanto.