何志强,刘兰娟.GRAS方法的改进及对比研究[J].数量经济技术经济研究,2018,(11):142-160 |
GRAS方法的改进及对比研究 |
A Comparative Study on the Improvement of the GRAS Method for Updating the Social Accounting Matrix and Input-Output Table |
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DOI: |
中文关键词: GRAS 超越方程 保号 保零 社会核算矩阵 投入产出表 |
英文关键词: GRAS Transcendental Equation Sign-preserving Zero-preserving Social Accounting Matrix Input-Output Table |
基金项目:本文获得教育部人文社会科学研究项目“提高劳动报酬占比的理论、实证与政策:基于CGE模型的研究”(12YJA790086)的资助。 |
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中文摘要: |
研究目标:改进GRAS方法,减少社会核算矩阵(SAM表)调平和投入产出表(IO表)更新的先验信息丢失。研究方法:对比GRAS及其改进的AGRAS、UGRAS、SGRAS、IGRAS等方法,针对保零、保凸、保号、无偏等特点,构建EGRAS方法,并进行了数值模拟。研究发现:综合AIL、Theil‘s U、GDM等误差指数,EGRAS方法具有保号、保凸、保零、无偏、避免正负项抵消等优点,并能有效保留先验信息,有推广价值。研究创新:构建保号、保凸、保零、无偏、避免正负项抵消的EGRAS方法进行SAM表调平和IO表更新,并无须定义0/0和0ln0值,而且可求全局最优解。研究价值:在SAM表调平和IO表更新时,减少先验信息丢失,提高调平的经济学含义。 |
英文摘要: |
Research Objectives: This paper effectively develops the methods of updating social accounting matrix and input-output table and minimizes information loss. Research Methods: The EGRAS method is constructed to compare with the GRAS method including the AGRAS、UGRAS、SGRAS and IGRAS. Then the method is applied to numerical simulation. Research Findings:Either calculation errors are made or different information gain measures are compared. The numerical results show that EGRAS which is unbiased and convex consistently outperforms both sign-preserving and strictly zero-preserving when increasing and decreasing cell values occur together. Moreover, EGRAS can overweigh large errors in small coefficients. Research Innovations:The research improves GRAS and forms the optimal model-EGRAS which unnecessarily defines 0/0 and 0ln0. Moreover, the global optimal solution can be found. Research Value:It‘s a core objective to decrease information loss and increase economic importance through EGRAS when updating the Social Accounting Matrix and Input-Output Table. |
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