偏离最优公共—私人投资比对经济增长的影响

The Effect of the Deviation from Optimal Public-Private Investment Ratio on Economic Growth in China

本文在假定存在最优公共—私人投资比的基础上,构建了一个偏离最优公共—私人投资比的程度系数并将其纳入Cobb-Douglas生产函数中,同时基于2003—2014年中国省级区域的相关数据,建立非空间面板模型与空间面板模型,以检验实际公共—私人投资比偏离最优公共—私人投资比是否对中国经济增长具有显著的负向影响。非空间面板模型结果表明:实际公共—私人投资比偏离最优公共—私人投资比将对中国经济增长产生显著的负向影响,而且根据估算出的最优公共—私人投资比而推算出的公共投资最优规模也存在着"发达地区<全国<欠发达地区"的关系;但无论是全国层面还是分地区而言,中国公共投资的实际规模总体上高于其潜在的最优规模。全国层面的空间面板模型分析得出了一致的结论。在考虑空间溢出效应后,估算出的最优公共—私人投资比在数值上稍微变小,从而使得推算出的公共投资最优规模有所下降,表明中国公共投资的实际规模相对更高。研究结果预示着在中国经济的未来发展中适度控制中国公共投资的实际规模是必要的。

Based on the assumption that there is an optimal public-private investment ratio,a deviation degree is defined to measure the deviation of actual public-private investment ratio from the optimal public-private investment ratio in this paper,and it is introduced into the Cobb-Douglas production function to construct a non-spatial panel model and a spatial panel model.By using the provincial level data of the period 2003-2014 in China,the results of the non-spatial panel model show that the deviation of the actual public-private investment ratio from the optimal public-private investment ratio has a significant negative impact on China’s economic growth.Moreover,the optimal scale of public investment also exhibits a relationship of“developed region<the whole of China<developing region”.However,the actual scale of public investment is generally higher than its potential optimal scale whether in the sample of the whole of China or in the samples of two regions.For the sample of the whole of China,the extended analysis of spatial panel model also supports the hypothesis proposed in this paper.When the spatial spillover effects are considered in empirical models,the estimated optimal public-private investment ratio becomes slightly smaller,which leads to a slight decline in the value of the estimated optimal scale of public investment.Therefore,the actual scale of public investment in China should be moderately controlled in the future.