创新能力、空间依赖与长三角城市群增长核心演化

城市群经济系统发展过程中，核心城市的增长极化与扩散作用是推动城市群协同发展的关键机制。创新能力、要素集聚与扩散形成的区际空间外部性使得城市群增长核心不断演化，并形成系统协同发展的内在动力。长三角城市群核心城市的极化效应呈现出下降趋势，对其主要影响因素的实证分析结果表明：创新分工过程中创新要素集聚与创新溢出、空间依赖都对城市极化效应具有显著影响。因此，政策导向应从强化城市间创新分工、充分利用创新过程的空间外部性、推进城市群协同发展的制度创新等方面着手。

Innovation Ability,Spatial Dependence and the Evolution of Growth Poles of Yangtze River Delta Urban System

During the economic development process of urban system ,the grow th polarization and diffusion effect of core city is the key mechanism to promote the coordinated development of city system .Based on the factors agglomeration and diffusion ,the economic relation and spatial externality are formed ,promoting the evolution of grow th poles and being the internal dynamic for the coordinated development of urban system .The polarization effect of the core city of Yangtze River Delta urban system decreased obviously .The empirical analysis on the main influence factors results show that the innova‐tional factors agglomeration and innovation spillover ,spatial dependence all have significant influences on the polarization effect of urban .Therefore ,the orientation of the policy should strengthen the innovation division of labor ,make full use of the spatial externalities of innovation process ,and promote the institutional innovation for coordinated development of ur‐ban system and so on .