城市经济学前沿问题研究进展

Evolution of Urban Economics:A Review of Theory and Empirical Methods

通过梳理城市经济学理论模型和实证方法的脉络,本文尝试厘清当前的系列前沿问题,其中包括:城市空间结构从单中心演变为多中心、城市发展从单一均衡到城市体系(城市间)均衡、微观集聚模式从同质性主体转变为异质性主体,以及实证方法逐渐从简约式估计演进为结构式估计。本文首先概述城市空间结构从单中心向多中心演变的机制、驱动因素以及经济社会效应;其次,阐释从单个城市均衡到城市间均衡的演变过程,探讨城市体系演变的驱动因素和相关议题;再次,剖析最新的异质性主体集聚理论,探讨异质性集聚的驱动因素和研究进展;最后,在实证方法上,概述从简约式估计到结构式估计转变的背景和研究进展。未来研究中,可关注远程办公、创新集群以及都市圈(城市群)一体化等对城市发展的影响。

China's economy is moving forward and striving for high-quality development,and clarifying the evolution of urban economics is essential to grasping the logic of urban development and telling China's story.In reality,several cutting-edge issues in urban economics have emerged,such as the transformation of urban spatial structure from monocentric to polycentric pattern,the industrial division of labor and functional positioning across large,medium,and small cities,and the sorting and selecting effects of heterogeneous agents(labor,enterprises,and industries)among different cities.Existing theories have not provided effective support or perfect explanations for these new phenomena.Reviewing the evolution of urban economics,this paper finds that spatial general equilibrium models have delved deeper,but there are still problems of overly rigid assumptions,an inability to effectively respond to reality,and a lack of complementarity between theory and reality.Specifically,urban economics has evolved from the Alonso-Mills-Muth(AMM)model to the Rosen-Roback model,and then to heterogeneous agents'agglomeration and quantitative spatial equilibrium models,consistently focusing on the spatial agglomeration of cities,and studying the flows and distribution of people and economic activities among cities.A series of frontier issues in urban studies have emerged.Therefore,to relax the assumptions of homogenous space,transportation costs,and competitive equilibrium,more reasonably explain the location choices of urban micro-agents,and apply more scientific methods to study diversified real-world problems,this paper summarizes the latest theories and methods in urban economics and looks ahead to future research directions.This paper focuses on four major frontier issues in urban economics.The first is the evolution of spatial structure within cities.In existing literature,measuring spatial structures based on the flow of factors like population or land serves as a research foundation,and the comprehensive analysis of the functional connections of units and their corresponding economic performance is the focus.The second is the division of labor and equilibrium among cities.Early studies mainly focused on measuring and evaluating urban size distribution,and then turned to the evolution of industrial specialization and the economic performance of intercity knowledge exchange among cities.The third is the heterogeneous agglomeration pattern.Heterogeneous agglomeration theory attaches importance to the spatial links among micro-agents with different characteristics,providing a micro-framework and new mechanisms to study the distribution and evolution of public service facilities,housing rents,labor,etc.within cities.The fourth is the quantitative spatial equilibrium analysis.As micro-level traffic network data becomes more widespread,the quantitative equilibrium analysis has gained prominence in urban and regional economics,involving topics like labor mobility,enterprise location,and infrastructure construction.Based on this,this paper provides an application example by constructing a model to determine city equilibrium size and conducting counterfactual analyses using China's urban data.In the future,using micro-level big data to study relevant topics may be indispensable for telling a good story with Chinese characteristics.These research topics include but are not limited to the following.(1)Expanding on the findings related to the impact of new information and communication technologies,such as telecommuting,on urban spatial structure.Telecommuting can significantly impact the patterns of labor agglomeration,and follow-up studies can consider the effect of telecommuting on labor commuting and introduce the differences in the efficiency of firms utilizing telecommuting to examine the changes in urban land rent curves.(2)Reinforcing the analysis of the impact of enterprise dynamics and innovation clusters on urban functional division and urban size.Further research can introduce the impacts of labor dynamics and knowledge accumulation on firms'production to explain the evolution of the functional division of labor among cities.(3)Strengthening the study of the relationship between heterogeneous labor mobility and public product supply in the context of metropolitan areas(urban clusters)integration.The development of public service networks can attract labor force inflows,especially in small and medium-sized cities with well-developed transportation networks and desirable living conditions within metropolitan areas.Future research directions may involve constructing efficient inter-city public service supply networks to promote coordinated regional development.