The Research Of The Effects Of Infrastructure Investment On China's Economic Growth

For the Chinese economy in the process of industrialization,infrastructure investment plays an important role in economic growth on demand side and supply side.In addition,the increase in infrastructure construction and the rapid growth of investment can increase the market demand for overcapacity industries such as steel and cement,which is an effective way to resolve excess capacity and realize the optimization of economic structure.Due to the important role of infrastructure construction in "steady growth" and "structural adjustment",China's infrastructure investment has grown rapidly and the scale of infrastructure has been expanding in order to achieve the dual goal of sustaining economic growth and easing overcapacity.Although China's total infrastructure construction is outstanding,The per capita level is very low and there is a big gap between developed countries.Therefore,there is still a lot of space in China's infrastructure construction,infrastructure investment in the next period of time will still have an important impact on China's economic development.By specifying a general equilibrium model including infrastructure investment,capacity utilization and economic growth,in this paper,we simulate the effects of infrastructure on economic growth under the two channels of "infrastructure?economic growth" and "infrastructure?capacity utilization?economic growth".And we analyze the mechanism of impacts of infrastructure scale and investment efficiency on economic growth and social welfare.The main conclusions are:1.Analysis on the impact channels of infrastructure investment on economic growth:(1)In the "infrastructure?economic growth" direct impact channel,infrastructure investment and economic growth has inverted "U" type characteristic.Infrastructure investment growth can not only directly promote the accumulation of capital,the multiplier effect increases the total society demand,but also promotes capital deepening resulting in long-term economic growth momentum.At the same time,the positive externalities of infrastructure investment have largely delayed the diminishing marginal returns of private capital.The role of infrastructure in economic growth is also negatively affected by the law of diminishing marginal production and the degree of congestion;(2)In the "infrastructure?capacity utilization->economic growth" indirect impact channel,through a variety of ways infrastructure investment effectively improve the capacity utilization to achieve an indirect role in promoting economic growth.Specifically,infrastructure construction has generated a large amount of demand for raw materials,which eases the excess surplus;the improvement of infrastructure can improve the quality of products and alleviate the situation of effective supply shortage to resolve the structural excess;the sound infrastructure can also reduce the depreciation rate of private capital and increase capacity utilization.(3)Based on the impact of the two channels,there is also a "U" type relationship between infrastructure investment and economic growth in the total effect of infrastructure investment on economic growth.The direct effects are linked to total effects and direct effect promotes capital accumulation and indirect effect improves the capacity utilization,which jointly promotes the economic growth.Since the contribution of infrastructure to capital accumulation through direct effect is much greater than indirect effect,the contribution of direct effect to output is more pronounced.2.In the impact of infrastructure on economic growth and social welfare mechanisms,the scale of infrastructure and investment efficiency is related to the role of infrastructure in economic growth.(1)infrastructure scale effect:in the aspect of economic growth,with the continuous growth of infrastructure investment,the network effect of various interconnection of infrastructure makes its role in economic growth gradually play,and the main mechanism of the role of infrastructure network in economic growth accelerates capital deepening;in terms of social welfare,with the continued growth of infrastructure investment,the scale effect has always had a positive impact on social welfare and shows consistency with economic growth.(2)investment efficiency:in terms of economic growth,with the expansion of infrastructure investment,investment efficiency will improve the level of infrastructure capital and optimize the structure of government spending,and promote economic growth,however,under the high level of infrastructure investment,the contribution of the improvement of infrastructure investment is very limited and leads to a decline in the level of output in the economy.In terms of social welfare,with the increase in infrastructure investment,investment efficiency has always been able to increase social welfare,and its impact on economic growth and welfare growth is inconsistent.Finally,the innovation of this paper is as follows:(1)In the research of infrastructure investment in economic growth,capacity utilization is often overlooked.In fact,infrastructure investment by improving capacity utilization to promote economic growth is an important aspect of its externalities.We examine the channel of "infrastructure?capacity utilization?economic growth".(2)Whether the existence of the scale effect and congestion,the current relevant research is less,so we integrate the scale effect of infrastructure into the dynamic general equilibrium model.(3)We are faced with the low investment efficiency and fixed asset delivery usage in the infrastructure construction process.We simulate the impact of infrastructure investment efficiency and utilization efficiency on economic growth,which is of practical significance for realizing high quality infrastructure investment.