Economic Analysis on Effects of Recurrent Resource Management on Global Warming through Global Timber Trading

我们的研究结果可以总结如下。1)在森林资源管理模型（DP-KYSS：九州林分模拟器动态规划模型）中，分析了森林经营实践对碳汇对减缓全球变暖的意义。这一分析表明，变薄会阻止碳固存的减少。考虑到补贴是对减薄碳损失的补偿，碳评估表明，根据补贴措施的不同，35年轮龄时单位碳损失成本的现值最高，50 ~ 65年轮龄时最小。在100年的轮调年龄，单位碳损失成本的现值为44.56至110.13欧元/公顷。分析表明，延长补贴期限将降低碳的价值。补贴越多，间伐越多，减少了林分中碳的封存。2)利用90年代九州7县442个城镇的数据，分析了森林退耕的经济机制。研究结果表明，人工林比例、城镇业主土地拥有率、林业工人密度等3个变量均降低了森林向休闲、工业和住宅的转化，表明在有利条件下进行的林业经营可以抑制森林的转化。3)我们把重点放在了宫崎县，那里的森林是日本最活跃的，重新造林的放弃是最普遍的。我们发现，大部分被采伐的森林在当年被重新种植，并且65%的采伐土地在第二年被重新种植，剩下的35%可能被遗弃。4)在日本进口木材中份额最大的北美木材的进口变化对新西兰木材需求的影响比对国内木材需求的影响更显著。美国房屋开工率和油价上涨10%，只会导致国内木材购买量增加1%。这意味着，即使实现减少从北美进口木材的目标，目前拥有有史以来最大数量的日本森林资源的利用仍然停滞不前，因此日本森林的可持续管理不是一件容易的事情。5)利用分结构住房需求方程系统考察了碳税对木结构住房需求的影响。结果表明，如果碳税的税率在政府目前提出的范围内，我们就不能指望通过引入碳税来大幅增加木制房屋的需求。为了加速新税出台的公告效果，需要通过启蒙活动向消费者宣传木质房屋在化石燃料消耗方面的好处，以及其他活动将消费者与木质房屋联系起来。6)我们提出了一个木材市场的林业部门模型，重点关注日本的八个地区（东北、关东、北陆、中部、近畿、中部、四国和九州）、中国和韩国。在估算价格弹性的基础上，通过JAFSEM （Japanese Forest Sector model）时空部分均衡市场模型分析了各区域的供需结构特征。我们的结果表明：1)九州和Chugoku的木材需求和供应的价格整体弹性较小，因为九州和Chugoku分别是国内木材和美国加工木材的生产区域活跃，2)关东这样一个消费面积大的地区木材需求的价格弹性较大，3)日本除九州以外的区域木材需求将增加，4)额外的木材需求将由韩国和中国满足。少

The results of our research can be summarized as follows.1)The significance of forest management practices on carbon sequestration for mitigating global warming was analyzed in the forest resource management model (DP-KYSS: dynamic programming model for Kyushu stand simulator). This analysis showed that thinning can prevents reduction of carbon sequestration. Considering subsidies as a compensation for carbon loss by thinning, the evaluation of carbon showed that the present net value of cost per unit carbon loss became the highest for the rotation age of 35 years and the minimum for the rotation age of 50 to 65 years dependent upon the subsidy measure. At the rotation age of 100 years, the present net value of cost per unit carbon loss was found to be 44.56 to 110.13 Euro/Ct. The analyses showed that lengthening the period for subsidy would reduce the value of carbon. Subsidy pays more with more thinning reducing carbon sequestered in a forest stand.2) We analyzed the economic mechani … More sms around forest conversion to other land uses using the data for 442 towns in Kyushu 7 prefectures in 1990s. We obtained the results that three variables, i.e., the percentage of plantation forests, the ratio of land owned by in-town owners, the density of forestry workers reduce forest conversion to each of leisure use, industrial use and residential use, which suggests that forestry management on-going under favorable conditions can brake forest conversion.3) We focused on Miyazaki Prefecture where forestry is the most vigorous and replantation abandonment is the most pervasive in Japan. We found that most forests harvested are replanted in the same year if it is replanted, and that 65% of harvested lands are replanted by the next year, leaving other 35% possibly abandoned.4) The change of timber imports from North American which has the largest share in the timber imported to Japan can have more significant effect on the demand for NZ timber than that for domestic timber. 10% increase of both housing starts and oil prices in the US only induces 1% increase of domestic timber purchased. This means that even if the decrease of timber imports from North America is realized, the utilization of Japan's forest resources which has now the largest ever volume is still stagnated and thus sustainable management of the nation's forest is not an easy task.5) We examined the effects of carbon tax on the demand of wooden houses using the by-structure housing demand equations system. Results illustrates that we cannot expect large increase of wooden housing demand from the introduction of carbon tax if the tax rate is in the range that the government is now presenting. In order to accelerate the announcement effect of new tax introduction, the enlightenment activity to appeal consumers the fact that wooden houses are good in terms of fossil fuel consumption, and other activities are needed to connect consumers to wooden house.6) We presented a forest sector model for lumber markets with a focus on eight Japanese regions (Tohoku, Kanto, Hokuriku, Chubu, Kinki, Chugoku, Shikoku, and Kyushu), China and Korea. With the estimated price elasticities for these regions, we analyzed the characteristics of the supply and demand structure through the spatial and inter-temporal partial equilibrium market model called JAFSEM (Japanese Forest Sector Model). Our results showed the following; 1) the price elasticities of lumber demand and supply in the whole are small in Kyushu and Chugoku, where production area of domestic timber and the US processed lumber, respectively is active, 2) the price elasticities of lumber demand is big in Kanto, such a prefecture with big consumption area, 3) Japanese regional lumber demand except Kyushu would increase, and 4) the additional demand for lumber would be met by Korea and China. Less