基础设施资本与经济增长--“倒U型”理论的经济逻辑与中国经验证据

Infrastructure Capital and Economic Growth: Economic Logic of the "Inverted U-shaped" Theory and Empirical Evidence from China

本文在Barro(1990)与Barro和Sala-I-Martin(1992)研究的基础上,将基础设施资本及其拥挤性纳入生产函数来构建经济增长的动态一般均衡模型,以此考察基础设施与经济增长之间的关系。其结果显示,稳态人均资本存量和人均产出与基础设施资本存量占比之间均呈现“倒U型”关系,且最优的基础设施资本存量占比是由生产资本的产出弹性、有效基础设施资本的产出弹性和基础设施资本存量占比的有效比重弹性共同决定的。为从实证上检验基础设施影响经济增长的理论命题,本文进一步建立静态面板模型并使用中国1993—2017年的省级面板数据进行估计,实证结果在证实人均产出与基础设施资本存量占比之间存在“倒U型”关系的同时,求解出“倒U型”顶点处所对应的最优基础设施资本存量占比为0.330,即当基础设施资本存量占比低于0.330时,人均产出随着基础设施资本存量占比的提高而上升;而当基础设施资本存量占比高于0.330时,人均产出则随着基础设施资本存量占比的提高而下降。

Based on Barro(1990)and Barro and Sala-I-Martin(1992),this paper examines the relationship between infrastructure and economic growth by incorporating infrastructure capital and its congestion into the production function to construct a dynamic general equilibrium model of economic growth.It is found that the steady-state capital stock per capita and output per capita have an inverted U-shaped relationship with the share of infrastructure capital stock,and the optimal share of infrastructure capital stock is determined by the output elasticity of production capital,the output elasticity of effective infrastructure capital,and the effective proportion elasticity of the share of infrastructure capital stock.To empiri-cally test the theoretical proposition that infrastructure affects economic growth,this paper further develops a static panel model and estimates it using provincial panel data for China from 1993—2017.The empirical results confirm the existence of an"inverted U-shaped"relationship between output per capital and the share of infrastructure capital stock,and solve for the optimal share of infrastructure capital stock at the apex of the"inverted Ushaped"to be 0.330,i.e.,when the share of infrastructure capital stock is below 0.330,output per capita increases as the share of infrastructure capital stock increases,while when the share of infrastructure capital stock is above 0.330,output per capita decreases as the share of infrastructure capital stock increases.