The world economy has entered a period of deep adjustment and the power of the economic recovery is still insufficient. At the same time, the geopolitical influence is aggravating and the uncertainty factors are also increasing. Under the above background, promoting economic growth, increasing employment and adjusting the industrial structure has become a consensus on international economic development. China’s economy is experiencing the most sustained growth slowdown since the reform and opening, and is in the new normal stage of phase transition. But the extensive economic growth pattern of "Happy Valley enclosure" was uncoordinated, unbalanced, inefficient and unsustainable in the early stage, which increased the structural risk of China’s economy. Currently, the imbalance of regional economic development is obvious in China, especially there is a huge gap between growth and income levels between the eastern coastal areas and the central and western parts of the mainland, which has formed the obvious "center- periphery" structure. The non-agricultural sectors’ agglomeration in the eastern coastal areas is considered to be a main reason of this structure. Therefore, from the two angles of efficiency and equity, regional coordinated development remains to be optimized.
Transportation infrastructure has transformed from a bottleneck of economic development to an accelerator. As an antecedent measure of The Belt and Road strategy and the important guarantee of new urbanization construction, the role of transportation infrastructure in economic development has attracted more and more attention of academia and government. But traditional economic theory focuses on the impact of transportation infrastructure on the economic system, which ignores the spatial characteristics and leads to the continuing conflicts between the constantly strengthened trend of industrial agglomeration and the general equilibrium conclusion in traditional theoretical analysis. The new economic geography introduced spatial factors into economic equilibrium analysis, and opened up a new era of economics research. However, the theoretical and empirical research on the economic agglomeration effect of transportation infrastructure in new economic geography theory is not enough, and the connection and interaction mechanism among transportation infrastructure, industrial agglomeration and regional economic development has not yet been clearly expounded. Therefore, it is necessary for us to comb the transportation infrastructure theory, establish an economic system including transportation infrastructure, and thoroughly analyze the relevance and interaction mechanism among transportation infrastructure, industrial agglomeration and regional economic development. Then we should objectively evaluate and analyze the sustainable development level of transportation infrastructure and its impact on the economic system, and point out its future development direction, finally provide some theoretical and policy support for the optimization of industrial layout and regional coordinated development in china.
Guided by the theories of industrial economics and new economic geography, this paper made a theoretical and empirical analysis of the relationship between the three basic factors of transportation infrastructure, industrial agglomeration and regional economic development, and the efficiency of transportation infrastructure development. In this paper, we adopted the research methods of the combination of normative analysis and empirical analysis, static analysis and dynamic analysis, comparison research and system research. The research route is as follows: firstly, we used the model of monopolistic competition of heterogeneous enterprises to analyze the situation of resource mismatches, and constructed the interaction mechanism of transportation infrastructure influencing the allocation of resources. Secondly, from the perspective of resource allocation, we introduced the transportation infrastructure variable into the new economic geography model of Martin (1995) to study the relationship and interaction mechanism among transportation infrastructure, industrial agglomeration and regional economic development; thirdly, we constructed a measurement system for the sustainability of transportation infrastructure and used DEA method to evaluate the sustainability of transportation infrastructure of different provinces in China, and further explored the reverse causality based on the relevant economic theory, which means studying the effects of industrial agglomeration and regional economic development on the sustainability of transportation infrastructure; finally, according to the empirical results, some policy suggestions are put forward.
The main conclusions of this paper are as follows:
First, the development of transportation infrastructure can effectively improve the efficiency of resource allocation. In this paper, we found that in the current economic development in China, the relative supply of factor resources is insufficient in the eastern region, while the central and western regions have relative surplus of factor resources. From the dynamic point of view, it was also found that the mismatch of capital elements in China was becoming more and more serious while the degree of mismatch of labor factors was gradually alleviated. The level of transportation infrastructure has a significant impact on resource allocation. The improvement of transportation infrastructure can mitigate or eliminate the mismatch of factor resources through the following three paths: one is to optimize the industrial location and promote structural adjustment, one is to reduce transportation costs and eliminate market segmentation, and the other is to expand market scope and improve the accuracy of division of labor. Investigating from a regional perspective, we also found that the influence coefficient of transportation infrastructure on resource allocation efficiency ranked the first in the east area, the second in the west areas and the third in the middle areas, which means that the effect of optimizing the resource allocation of transportation infrastructure will also be affected by the level of regional economic development.
Second, industrial agglomeration plays a part of intermediary role in the influence route of transportation infrastructure on regional economic growth, and the mediating effect depends on the interaction between the centripetal force and the centrifugal force in the region. The impact of intra-regional and inter-regional transport infrastructure on regional income is not consistent in different regions. The upgrading of intra-regional transportation infrastructure can promote the growth of per capita income in the region. The upgrading of the inter-regional transportation infrastructure in the eastern region will also help improve the income level of the local residents. However, the upgrading of the inter-regional transportation infrastructure in the central and western regions will have a negative impact on the local residents’ income. Besides, the spatial spillover effect of intra-regional transportation infrastructure is not obvious, but that of inter-regional transportation infrastructure is obvious. Among them, the spatial spillover effect is positive in developed areas, while the spatial spillover effect of the less developed areas is negative.
Third, the sustainability of transportation infrastructure development in China needs to be further improved, and there is a significant gap between regional transportation sustainability. In this paper, we found that the sustainability of railway transportation in China was characterized by "inverted U", which was located in the high growth range of 0.6135-0.7287 with 0.6797 as the center, but still had more room for improvement. Sub-regions investigating found that, the sustainability of rail transportation in eastern China is obviously better than that in the central and Western regions. The sustainable performance values of railway transportation in the east, middle and west regions were 0.7784, 0.6188 and 0.6270 respectively. The sustainability of railway transportation in the East and Midwest has been dispersed since 2009, after a period of convergence.
Fourth, the sustainability of transportation infrastructure development is affected by regional manufacturing agglomeration and environmental regulation. We found that the agglomeration degree of regional manufacturing industry had a significant negative correlation with the sustainability of railway transportation. It implied that the crowding effect of agglomeration in our country was beginning to appear, leading to the rise of the cost of railway infrastructure investment and operation, and increasing environmental pollution. We also found that there is no significant correlation between environmental regulation and railway transportation sustainability. It was pointed out that the effect of the current environmental regulation intensity on promoting sustainability was still to be improved. But the level of regional economic development and population density are positively related to the sustainability of railway transportation.
In general, compared with the existing literature, the research on the relationship between transportation infrastructure, industrial agglomeration and regional economic development in this paper has the following innovations: first, the innovation of the perspectives of the study. This paper studied the economic development of the region from the perspective of resource allocation. The impact mechanism of transportation infrastructure on resource allocation was constructed for the first time, and the existence of the mechanism was tested empirically, which laid a theoretical foundation for further research. Second, based on the principle of new economic geography, we introduced transportation infrastructure and constructed a new spatial economic model. Through the deduction of the model, the influence of transportation infrastructure on industry agglomeration and regional economic growth was studied theoretically. This paper first presented and explained the intermediary role of industrial agglomeration in the path of transportation infrastructure affecting regional economic growth. Third, this paper constructed a sustainable development evaluation index system of transportation infrastructure, and used the network DEA model to evaluate the performance level of railway infrastructure sustainability in China for the first time. We then integrated the value with the panel data at the provincial level and used the Tobit regression model to explore the reverse causality, which means analyzing the influence of industrial agglomeration and regional economic development on the sustainability of transportation infrastructure.