长江经济带区域协同增长的关键在于明确沿江城市群内部城市间产业联系对其经济产出的影响.城市群内部城市间的产业联系会加强其间的知识溢出并分享超额利润,从而影响城市群的经济产出.分析城市群内部城市间产业联系对经济产出的影响机制,构建理论模型.针对传统引力模型的不足,采用行业间投入产出引力模型(IIG模型)估算了2001-2015年间长江经济带沿线城市群的产业联系,通过产业联系修正人力资本的有效性.采用非参数协方差矩阵估计方法验证了理论模型.分析结果表明,以传统引力模型估算产业联系时,无法验证产业联系对经济产出影响的正面作用,而使用IIG模型估算产业联系时则能验证,即验证了理论模型,也说明了IIG模型对引力模型改进的意义.

针对学界在研究产业集聚份额比例对经济产出影响时存在的不同观点,文章在分析城市产业集聚模式特征时,在产业集聚的份额比例之外加入反映相关产业集聚的相关关系系数.通过理论分析,指出一定程度相关性集聚对区域经济产出的作用是正向的,而在相关关系系数超过门槛后,其影响则是负向的,即该种影响是倒U型的,并以此为依据构建理论模型.以1998-2015年长江经济带109个地级以上城市为研究样本.通过数据检验,确定模型形式为个体固定效应,运用非参数协方差矩阵估计方法对样本城市进行经验分析,对理论模型的有效性进行了验证,验证了相关产业集聚对经济产出的“倒U型”影响.

Through theoretical analysis , this paper assumes that the effect of the relevant agglomeration mode on economic output is inverted U.Namely, a certain degree of relevant agglomeration will accelerate the knowledge spillover between the relevant industries .Too much relevant agglomeration will make the regional economy fall into path dependence and increase the possibility of regional economic stagnationsuffered from economic shocks .On this basis, it constructs the analytical mod-el, takes China 226 prefecture level cities from 1998 to 2003 years as a sample, selects individual fixed effects model and u-ses nonparametric covariance matrix estimation method for the empirical analysis .Results verify the hypothesis of the theo-retical model, that is, the impact of the relevant industrial agglomeration on economic output is “inverted U”.According to the conclusion , the corresponding optimization directions are given for different types of cities .

Megalopolis is the focus and engine of national development. Its deifnition and division criteria are the basis of theoretical research and planning practice.Based on the systematic review of the controversy and common understanding of existing research, this paper considers that the root cause of controversy of the definition and division is the excessive emphasis on performance standards. Economic links between cities have a decisive effect on the formation of megalopolis.,Therefore, to strengthen the deifnition and division of megalopolis from the link standards, can effectively avoid the debate of performance access standards in deifning and dividing. In view of the problem of not considering the input and output relations between cities of the traditional gravity model, the paper puts forward inter industry input-output gravity model to measure economic links between cities, and regards it as the deifnition and division standard of Chinese megalopolises.

城市群经济绩效与其内部城市间的各种联系密切相关,对城市群内部城市间联系的测度是实现城市群健康发展的基础.传统引力模型测算城市间联系时,忽视了产业分工关系对其联系的影响,也无法诠释城市联系的驱动来源,论文从城市间产业投入产出关系出发,构建行业间投入产出引力模型.通过该模型在对中国28个城市群范围划分的基础上,测算了城市群的联系强度,并对联系强度的驱动因素进行了分析,最后从产业规模调整、产业结构协同与交通网络建设三个方面对不同城市群提出针对性的政策建议.

本文将对城市空间布局形态、城市交通系统、城市交通发展战略等进行综合分析,得出不同城市空间布局下的城市交通发展战略,并在此基础上以西安为例,对空间布局与交通发展战略进行具体分析。