中国四大林区固碳效率:测算、驱动因素及收敛性

论文将林业碳汇纳入到林业经济核算体系之中,构建含有正外部性产出的DEAMalmquist效率分析模型,在系统测算林业固碳量的基础上,对1988—2013年中国四大林区的林业固碳效率变动及驱动因素进行了分析,并进一步对其效率收敛性进行了检验。研究结果表明:1)全国四大林区间的固碳量及固碳价值差异较大,固碳总价值从高到低依次为西南(1 870.69×108元)、东北(1 335.41×108元)、南方(842.73×108元)、北方林区(407.35×108元)。2)1988—2013年不含碳汇产出的林业生产Malmquist指数较低,为0.958;而把碳汇纳入林业产出进行考量,全国林业Malmquist指数整体有所提升,主要源于技术效率推动,年均增长速度为0.6%;其中南方、东北林区固碳效率处于提升状态,而西南林区和北方林区呈下降趋势。3)西南和南方林区固碳效率随时间变动呈现倒"U"型态势;四大林区中南方林区效率均值最高,为1.036,其次是东北林区,为1.020。4)我国四大林区地区间固碳Malmquist指数没有出现σ收敛,相反,还存在绝对β发散现象,即四大林区地区内的林业固碳效率绝对值和增长率差异并没有随着时间而缩减。

Carbon Sequestration Efficiency of Four Forest Regions in China: Measurement,Driving Factors and Convergence

This paper brings forestry carbon sequestration into the forestry economic accounting system, building a DEA-Malmquist index containing positive externality output. Based on the systematic measurement of forestry carbon sequestration, it estimates forestry production efficiency and the driving factors of the four forest regions of China from 1988 to 2013, and then using σ convergence and absolute β divergence analysis method, it checks the convergence of forestry production efficiency. The results show that: due to the differences of forest intensive degree and industrial development, the carbon sequestration and carbon sequestration value also have big difference among the four forest regions, the total output values of carbon sinks from high to low are: in the first place, the carbon sequestration value in the Southwest Forest Region is 187.069 billion yuan; in the second place, the carbon sequestration value in the Northeast Forest Region is 133.541 billion yuan; came in the third place is the South Forest Region, the carbon sequestration value being 84.273 billion yuan; on the bottom of the list is the North Forest Region, the carbon sequestration value being 40.735 billion yuan. The Malmquist index without considering the carbon output of forestry production is low, 0.958. When taking the carbon sink of forestry output into consideration, the efficiency is then improved at an average annual growth rate of 0.6% from 1988 to 2013, and the main reason is the improvement of technical efficiency. In the South Forest Region and Northeast Forest Region, the production efficiencies are in the upgrading trend, while in the Southwest Forest Region and North Forest Region, the production efficiencies show downward trend. The efficiencies in the Southwest Forest Region and South Forest Region have a tendency of inversed “U”-shape with the change of time. The average efficiency of the South Forest Region is the highest, which is 1.036, followed by the efficiency of the Northeast Forest Region, which is 1.020. The Malmquist index does not show σ convergence in the four forest regions of China, and there is a phenomenon of absolute β divergence, which means that the differences of the absolute values and the growth rates of the forestry production efficiencies in the four forest regions do not reduce with time.