基于随机投入产出模型对CO_2排放系数的估计

Consistent and Unbiased Carbon Dioxide Emission Multipliers

本文从最终消费的角度来计量CO2排放,其中包括最终消费导致的直接排放和间接排放,本文把单位最终消费导致的CO2排放量称为完全CO2排放系数。计算完全CO2排放系数的传统方法是使用单位产品的直接CO2排放系数乘以里昂惕夫逆矩阵。这种方法的主要问题包括:一要确保矩阵可逆且逆矩阵系数非负;二缺乏统计属性,无法进行参数检验和区间估计。所以,本文利用随机投入产出模型,采用产出表和使用表的数据代替对称的投入产出表的数据,计算得到了我国2007年产品部门的完全CO2排放系数的无偏估计,并得到排放系数的置信区间。并与传统方法计算的系数进行了比较,传统方法计算的系数存在较小的高估。接着,文章又利用随机投入产出模型计算了我国对国外CO2排放的影响程度,结果表明我国对国外的CO2排放的影响较小。

This study attempts to measure carbon dioxide（CO2） emissions from the point of final consumption.Final consumption is responsible for direct and indirect emissions.The CO2 emission by per unit of final consumption is called the CO2 emission multiplier.The traditional method for obtaining the multipliers is to use per unit of product’s direct CO2 emissions multiplied by the Leontief inverse coefficient matrix.In general,this method has three problems：1） it must make sure that the matrix can be inversed and the coefficients of the Leontief inverse coefficient matrix are not negative;2） it has no property of statistics so that it cannot perform hypothesis testing and obtain the interval estimation;and 3） the multiplier derived by this method is unbiased.Therefore,a stochastic input-output model was used,which uses supply and table instead of the symmetric input-output table,to calculate the unbiased and consistent carbon dioxide emission multiplier and obtain the confidence intervals of the carbon emission multiplier.For comparing the differences between the two methods,the two methods were used to calculate the multipliers.Results show that the traditional method is a little biased.The products’ CO2 emissions show that the chemical industry and fabricated metal products take up 29.5% and 27.8% of the total emissions,respectively.Top five products of the direct emissions multipliers are fabricated metal products,chemical industry,transportation,storage and post and communications,and mining and electricity,heat,gas,water production and supply industries.However,top five emissions multipliers are fabricated metal products,chemical industry,electricity,heat,gas,and water production and supply,construction and manufacturing.In particular,construction and manufacturing have a larger influence on CO2 emissions from the point of consumption,since the two products have higher indirect CO2 emissions.Then,a stochastic input-output model was used to analyze carbon emissions of foreign countries due to China’s final products.Results show that China has a little influence on foreign carbon emissions.The results are greatly different from that of Denmark,which has an important influence on CO2 emissions in other countries