中国劳动报酬份额变化的动态一般均衡分析

A Dynamic General Equilibrium Analysis of the Evolution of China’s Labor Income Share

为了更好地解释过去20年来中国劳动报酬份额呈现的U型变化模式,本文构建了一个开放经济下的动态一般均衡模型。通过将偏向型技术进步、资本动态及国际贸易等因素纳入模型,较好地模拟了2000—2017年间整体劳动报酬份额的U型变化特征,并捕捉和量化了生产率冲击、偏向型技术进步冲击、投资冲击、劳动力供给冲击及贸易成本冲击等多类冲击在解释劳动报酬份额变化中的相对重要性。研究发现:(1)偏向型技术进步冲击是解释中国劳动报酬份额U型变化的主要因素,中国整体劳动报酬份额的上升有70%以上可归因于2007年后中国可贸易部门与不可贸易部门的技术进步偏向类型的改变。(2)在结构因素中,90%以上的解释力来自部门内效应,而非部门间的结构变化。(3)在各种冲击因素中,来自中国自身的冲击是主要的,其他国家冲击的解释力度相对较弱。(4)数值模拟显示,改善投资效率、提高贸易自由化水平与提升全要素生产率均会进一步提高我国当前劳动报酬份额。本研究有助于增进对我国近年来劳动报酬份额变化模式的理解,同时也为当前改善国民收入分配格局以推动共同富裕提供了一定的启示。

In the past decades,the decline of labor income share in China has aroused extensive discussions among a bunch of scholars.Yet,a growing body of evidence in recent years suggests that the labor income share of China has seen a significant U-shaped evolution,especially since China’s accession into the WTO.In the meantime,China’s trade dependence,which means the ratio of total exports and imports to GDP,shows an obvious inverted U-shaped curve,with the large expansion of China’s non-tradable sector and the rapid shrinkage of tradable sector after the financial crisis;while the labor income share in both sectors features a U-shaped change.These stylized facts highly attract our attention and we then propose the following research questions:Why does the labor income share in China evolve into a U-shaped curve in the past 20 years?What on earth drives such evolution?And what are the relationships between these stylized facts?To answer these questions,we first investigate forces acting on the U-shaped evolution of China’s labor income share between 2000 and 2017 based on a dynamic general equilibrium framework,and then quantitatively analyze and evaluate their contributions to the U-shaped change by adopting counterfactual analysis.To be specific,theoretically,we set up a dynamic multi-country and multi-sector general equilibrium model,which incorporates biased technical progress,capital dynamics,and international trade.This framework allows us to well characterize the U-shaped evolution of China’s labor income share between 2000 and 2017 and identify the following shocks:(1)the total factor productivity shocks of different sectors,(2)the sectoral level investment shocks,(3)the labor supply shocks,(4)the aggregate demand shocks,(5)the trade cost shocks,and(6)the sectoral level biased technical progress shocks.Using this model,we can estimate these different dynamic shocks and assess their contributions to the U-shaped evolution of the labor income share in China.Counterfactual quantitative analyses show that the biased technical progress shocks of different sectors are the primary explanations of the U-shaped evolution of labor income share in China.Particularly,the direction of technical progress which turned to be labor-biased from capital-biased after 2007 can account for over 70%of the increase of China’s labor income share in recent years.Furthermore,on average,the shocks’intra-sectoral effect,instead of inter-sectoral effect,account for over 90%of the U-shaped change of China’s labor income share.Moreover,foreign shocks play minor roles,while China’s internal shocks mainly explain the U-shaped evolution,which implies that Chinese government can use several policy instruments to improve the labor income share in the future.Numerical analysis shows that the decline of the trade barriers,the improvement of the investment efficiency and the total factor productivity improvement are three important instruments that Chinese government can take to further increase the labor income share of China.Income distribution has long been the core issue in studies on Chinese economy,and the evolution of the labor income share in China has received heated attention from economists.Although a few research have explored the possible reasons for the U-shaped change of China’s labor income share from different aspects(e.g.,factors),the research perspective still focuses on single dimensions such as structural transformation and specific policies and systems,and existing research is mostly based on the traditional analysis method.However,factors that affect the change of labor income share at macro level are complicated and different impacts may interact with each other.Even if there are as many control variables as possible in research,the traditional reduced-form empirical analysis might still be plagued by endogeneity problems.At the same time,simply exploring from a certain angle may not be able to disentangle the real reason that leads to the U-shaped evolution rule of China’s overall labor income share.Our study fills in this gap by integrating the structural transformation between tradable and non-tradable sectors,intra-sector effects,biased technical progress,capital dynamics,international trade and other factors into the dynamic general equilibrium analysis framework.This paper allows us to investigate the driving forces acting on the U-shaped evolution of China’s overall labor income share from 2000 to 2017 in a unified framework,which further supplements and enriches existing research on determinants of China’s labor income share.The findings,therefore,helps to provide a richer understanding of the U-shaped evolution of China’s labor income share in the past decades,and have important policy implications for further improving the pattern of national income distribution.