中国潜在产出的综合测算及其政策含义

Estimation of China's Potential Output and Its Policy Implications

本文分别利用生产函数法、状态空间模型、宏观计量经济模型及DSGE模型四种方法,对我国1993-2018年的潜在产出进行了估算,详细分析了其变动原因和政策含义,并给出未来10年的趋势预测。主要结论有:(1) 1993-2018年我国潜在产出呈现出逐步放缓走势,平均增长率为9. 4%,略低于9. 5%的实际GDP平均增长率。其中,全要素生产率趋势平均增速为3. 6%,资本投入平均增速为11. 7%,劳动力投入平均增速为0. 6%,对潜在产出增速的平均贡献率分别为38. 3%、58. 3%和3. 4%。(2)近年来潜在产出增速的趋势性放缓主要源于高投资并未形成有效资本,进而导致有效资本投入对潜在产出的拉动力持续走低。而投资专有技术进步放缓,投资调整成本上升,资本形成效率快速下降,是有效资本投入不足和潜在产出放缓的深层次原因。这也是供给侧结构性改革的理论基础。(3)劳动力市场搜寻成本较高,供需结构不匹配,导致劳动的增长贡献率较低,我国的人口优势并未得到充分利用和有效发挥,进一步加剧了近年来潜在产出增速的趋势性放缓。(4)如果不推动供给侧结构性改革,未来5-10年我国潜在产出平均增速仍将缓慢下降。与发达经济体相比,我国潜在产出增长仍有较大提升空间,尤其在劳动投入方面。(5)政策上,应在平衡好短期需求与中长期改革目标基础上,以结构性改革为导向,完善劳动力市场,提高劳动力质量,降低就业主体的搜寻成本。着力促进全要素生产率提升,更加注重优化投资质量和结构,提高投资专有技术进步水平。

Over the past decade,China's macroeconomic operation has shown a more obvious trend.The growth of major macroeconomic indicators has slowed down.The average growth rate of real GDP declined from 13%to 6.6%before the crisis;the growth rate of total retail sales of consumer goods and investment in fixed assets dropped rapidly from over 20%in 2008 to about 6%and 9%,respectively;and the growth rate of M2 declined from 16%before the crisis to a historic low of 8%.Although theoretical and policy discussions proposed many different explanations for this phenomenon,there is still a lack of adequate quantitative analysis.In general,when inflation is basically stable,the long-term downward trend in economic growth usually results from the change of potential output growth rate.What is the current trend of potential output in China?What factors influence the trend change?Will this trend sustain for a long time?The answers to these questions are not only the focus of theoretical research,but also key to the decision-making of future macro-policies.Measuring potential output and output gap is particularly important for central banks,as they not only are the core objectives of monetary policy,but also enter the monetary policy decision-making rules directly,which affect the operation of the whole policy.Unfortunately,both potential output and total factor productivity(TFP)are unobservable state variables and can only be estimated from various methods or models.Therefore,it is of great theoretical and practical significance to effectively estimate China's potential output,to analyze the impact of different factors on potential output,and to carry out medium-and long-term trend prediction.In this paper,we first give a brief overview of the current mainstream methods for estimating potential output and compare their characteristics and applicability.Second,we estimate the potential output of China from 1993 to 2018 though four methods,including production function method,state space model,macro-econometric model and DSGE model from the perspective of monetary policy decision-making.Next,we analyze and forecast the causes and trends of potential output changes.Finally,the main conclusions and corresponding policy implications are obtained.The main conclusions are as follows.(1)The average growth rate of China's potential output from 1993 to 2018 is 9.4%,slightly lower than that of real GDP at 9.5%.The average growth rates of TFP trend,capital input and labor input are 3.6%,11.7%and 0.6%,respectively,while their average contribution rates to potential output growth are 38.3%,58.3%and 3.4%,respectively.Overall,the trend of potential output growth rate in China shows a clear periodic characteristic.(2)The slowing down trend of potential output growth in recent years is mainly due to the decline of the growth rate of effective capital input which leads to the continuous decline of the pull of capital input on potential output.The slow progress of investment-specific technology,the rising cost of investment adjustment and the rapid decline of capital formation efficiency are the deep-seated reasons for the change of the growth rate of effective capital investment.(3)The low contribution rate of labor growth leads to the underutilization and effective exertion of China's population advantage,and further aggravates the slowdown of potential output growth in recent years.(4)In the next 5-10 years,the average growth rate of China's potential output will continue to decline slowly and stabilize in the range of 4.8%to 5.1%.However,compared with developed economies,China still has considerable room for improvement in potential output growth,especially from the area of labor input.This paper proposes the following suggestions.(1)In balancing short-term demand and medium-term and long-term reform objectives,we should stabilize investment growth and pay more attention to optimizing the investment structure and improving investment quality,capital formation efficiency and the level of investment-specific technology progress.(2)We should further improve the labor market,reduce the searching and matching cost of employment,improve labor quality and the matching degree of demand,and reduce ineffective supply to increase the contribution rate of labor input.(3)Institutional mechanism construction should be strengthened to further promote structural reform.While deepening the implementation of innovation-driven strategy and increasing R&D investment,we should take various measures to promote the overall improvement of TFP.(4)Faced with the trend change of potential output,we should pay attention to the identification of macroeconomic trend change and cyclical fluctuation in making monetary policies,strengthen policy coordination,grasp the implementation of policies,and improve the accuracy of policy response.