公共R&D投资的生产率效应与结构效应——基于制造业部门面板数据的实证分析

The Empirical Analysis on Productivity and Structure Effects of China's Public R&D

实施创新驱动发展战略、强调科技创新是提高全社会生产率和综合国力的战略支撑,必须摆在国家发展全局的核心位置。近年来,国家财政科技支出快速增长,评价公共研发投资的生产率效应和结构效应势在必行。基于公共产品的视角,通过将公共R&D资本服务和技术进步引入列制造业成本函数,运用大规模微观非平衡面板数据集的20个两位数制造业部门企业数据,估计了行业的平均成本函数及要素份额函数,测算了公共R&D的平均成本弹性、要素需求弹性以及边际效益。研究发现:总体上看,样本期内公共R&D的生产率效应不够明显,但结构效应更为显著,普遍增加了制造业对劳动力的吸纳能力,导致所有行业的资本一劳动比和中间品一劳动比均有下降,提高了劳动力与物质资本、中间品的搭配比例,促进了二元经济向一元经济的转换,而对近年来增长较快的制造业部门要素配比影响较弱。公共R&D投资在耐用品制造业部门的边际效益更大。本研究为政府的行业公共R&D投入政策提供了参考建议。

Implementing innovation-driven development strategy and emphasizing on technological innovation provide strategic support for enhancing overall social productivity and comprehensive national power, and thus should be placed at the core of national development. In recent years, public expenditures on science and technology in China has grown rapidly. An evaluation of public R＆D investments on productivity and structure is imperative. From the perspective of public goods, this paper incorporates capital services and technological advances of public R＆D into the cost function. Using large-scale unbalance panel data of 20 manufacturing firms sorted by two-digit codes during the period from 2001 to 2007, this paper estimates the cost functions and factor shares of various sectors and calculates the cost elasticity of public R＆D, price elasticity of factor demand and marginal benefit of public R＆D. We find that the effect of public R＆D on productivity is not significant while its effect on structure is. It may be a substitute or complement to labor, capital and intermediate good, depending on the sector. This paper provides suggestions on the government＇s investment policy in public R＆D. ical philosophy.