中性技术进步下不变要素替代弹性估计与检验

Estimation and Test of the Invariant Elasticity of Elements Substitution in China with Neutral Technological Progress

投入要素替代弹性因涉及到经济增长状态、经济体向稳定状态的收敛速度和单位资本产出水平等重要的宏观经济问题而备受关注。本文利用等产量线上投入要素数量和价格相对变化比的等价变换提出了替代弹性的回归方程计量估计法,其可以避免现有主流估计方法因为前提条件的限制等原因而具有丧失一般性及重复利用信息的问题。但难点转移到了不同时期等产量线上投入要素数据的获取方面。在中性技术进步、充分竞争和规模报酬不变的条件下本文证明了,利用现有样本信息得到的资本劳动数量比恰等于对应时间点上,和期初同等生产能力、等产量线上所需投入要素数量比。最后,利用1990-2015年数据,对我国资本-劳动投入要素替代弹性进行了平均和变结构估计与检验,得到样本期内我国平均要素替代弹性小于1,但1998年前后资本-劳动替代弹性明显不同,当前阶段(1999年以来)不能拒绝"要素替代弹性为1"的原假设等结论。研究表明我国经济体的生产能力正处于灵活且稳定的发展阶段。

The substitution elasticity of input factors has attracted much attention because it involves such important macroeconomic issues as the state of economic growth,the rate of convergence of the economy to a stable state and the level of unit capital output.A regression equation econometric estimation method is proposed by using the equivalent transformation of the relative change ratio of the quantity and price of input factors on the equal output line,which can avoid the problem of losing generality and reusing information due to the limitation of preconditions in the existing estimation of substitution elasticity of input factors.However,the difficulty has shifted to the acquisition of input factor data on equal production line in different periods.Under the conditions of neutral technological progress,full competition and constant returns to scale,it is proved that the ratio of capital to labor obtained from the existing sample information is exactly equal to the ratio at the corresponding time point,with primary production capacity and the number of input elements required on the equal production line.Finally,using the data from 1990 to 2015,we estimated and tested the substitution elasticity of input factors in China,and found that the average substitution elasticity of input factors in China is less than 1,and which around 1998 has different structural characteristics.At present,we can not refuse the original assumption that the substitution elasticity of input factors is 1,which indicates that our economy is in a relatively flexible and stable stage.