| Accompanied with the narrower spatial distance and the closer economic relations in cities,the construction of urban agglomerations has become an important platform and means to promote the optimal allocation of regional factor resources and coordinate regional economic development.The construction of urban agglomerations in the mid-west regions were started later than the eastern regions,and it is still in the stage of exploration and development.In-depth discussion of the innovation effects and regional innovation spillovers in the construction of the mid-west urban agglomerations has a significant meaning.It will not only help to narrow the economic gap between the mid-west regions and the eastern regions,but also can tap the new momentum of economic development in the mid-west regions.Based on this,this paper systematically sorted out the relevant theories of the urban agglomeration construction on urban development and regional innovation capability,and investigated the innovation effect and regional spatial spillover effect of the construction of the mid-west urban agglomeration.Firstly,analyzed the innovation ability of the mid-west urban agglomerations to the central city by the Synthetic Control Method(SCM).The result shows that the construction of the mid-west urban agglomeration has a significant positive impact on the innovation capacity of the central city,specifically the central city of Wuhan,Zhengzhou,Xi’an,and Chengdu bring 14.08,3.31,9.92,and 16.77 innovation growth effects.Through a series of robust tests,such as Difference in Difference test,Time-event test,and Placebo test,we found that the benchmark results are still robust.A further mechanism test found that the resource agglomeration capacity of the central urban agglomeration is relatively weak,and the role of urban agglomeration construction in promoting human capital and investment scale is not obvious.At the same time,the construction of mid-west urban agglomerations has a significant negative impact on the level of knowledge input and output,it shows that the construction of mid-western urban agglomerations has insufficient motivation for talent introduction.Then,analyzed the spatial correlation of the four major urban agglomerations by the Social Network Analysis Method.The results show that there is a "universal connection" between the cities,and the network accessibility is strong.Among them,Wuhan and Chengdu are net spillovers,showing innovation spillover effects to surrounding cities.The spillover relationship and benefit relationship in Xi’an are equal,and there is no obvious spillover effect.Zhengzhou is a net beneficiary,and the surrounding cities still present a "blood transfusion" status to Zhengzhou.From the perspective of centrality,the central cities of the western urban agglomeration have a stronger influence on the surrounding cities,the central urban agglomeration has a weaker control of the central cities,and the development of innovation capabilities of the cities is more balanced.Combining the above conclusions,the policy enlightenments of this article are as follows,firstly,more active and targeted policies should be issued to the mid-west urban agglomerations,so as to enhance the integration capacity and innovation effect of the mid-west urban element resources;Secondly,it is necessary to give full play to the radiation and demonstration effects of mid-west cities and create an innovative sharing mechanism for inter-regional urban agglomerations. |
