Urban evolution in the USA

On a sustained basis, cities are of non-uniform relative sizes.This paper addresses three basic issues which arise from thissimple observation by examining the size distribution of UScities over the period 1900–1990. First, we explore thereasons why there is a wide distribution of city sizes. Second,we characterize the evolution of the size distribution of cities,documenting growth in sizes and numbers of cities. We ask whetherthe relative size distribution of cities has remained stableover time, or if it has displayed, instead, a tendency to collapse,flatten, or otherwise change its shape. We also examine evidenceon whether the size distribution obeys Zipf's Law. Third, weexamine the degree and determinants of mobility of individualcities within this distribution, asking to what extent citiesare moving up and down in the distribution and how this movementis influenced by cities' geographic characteristics. We usea newly constructed data with consistent metropolitan area definitionsover this century, discussing the issues and linking our resultsto the relevant literature.     

湖南省市镇规模等级结构的动态研究

本文应用市镇人口规模分布理论,研究了湖南省城市人口规模分布结构的动态变化及其基本特征。同时构造了2000年湖南省市镇序秩--规模分布模型,并利用logistic函数对预测结果进行了验证。预测表明:2000年南省市镇人口、市镇化水平分别约为2174万和32%,特大城市和大城市将扩大为长沙、衡阳、湘潭、株洲、岳阳和常德六市。据此对2000年湖南省市镇等级体系进行了规划。     

Urban Hierarchy and the Rank-Size Distribution

The paper analyzes some connections between the rank-size distribution of cities and central place population models. Compatibility conditions with the rank-size distribution are determined for the models considered. The values for two specific parameters under these conditions are determined, and additional interpretations of the rank-size distribution are suggested.     

On the Rank-Size Distribution for Human Settlements

An explanation for the rank-size distribution for human settlements based on simple stochastic models of settlement formation and growth is presented. Not only does the analysis of the model explain the rank-size phenomenon in the upper tail, it also predicts a reverse rank-size phenomenon in the lower tail. Furthermore it yields a parametric form (the double Pareto-lognormal distribution) for the complete distribution of settlement sizes. Settlement-size data for four regions (two in Spain and two in the U.S.) are used as examples. For these regions the lower tail rank-size property is seen to hold and the double Pareto-lognormal distribution shown to provide an excellent fit, lending support to the model and to the explanation for the rank-size law.     

中国城市群空间结构演化的影响因素分析——基于铁路客运的功能联系视角

以中国13个城市群为研究对象,采用铁路客运班次构造多中心指数来表征基于功能联系的城市群空间结构,在分析城市群空间结构演变基础上重点分析其影响因素。研究发现,基于功能联系视角的城市群空间结构总体呈单中心化趋势,但地区差异化明显,珠三角、山东半岛和闽东南城市群已表现出多中心化特征;城市群空间结构的多中心程度随经济发展水平的提高表现为先单中心后多中心的演变过程;城市群规模的增大和城市间联系加强促进了城市群向多中心方向演化;而面积小、三产比重高的城市群更有利于形成单中心的结构;政府干预作用对城市群空间结构影响并不显著。鉴于不同城市群空间结构演化趋势不同,未来政策取向应该遵从各个城市群自身规律。     

基于分形理论的长株潭城市群等级规模结构研究及对策

运用城市群等级规模结构分形理论和方法,对长株潭"3+5"城市群(以下简称"3+5"城市群)的等级规模结构进行了实证研究,通过测算几年来"3+5"城市群等级规模分布的分维值,得出结论:"3+5"城市群规模分布符合分形特征;模型拟合认为其人口、经济分布的分维值均大于1,表明"3+5"城市群等级规模结构集中,已处于发展的相对成熟阶段。为此在对这些特征做出解释的基础上,认为可从强化首位城市、加快长株潭一体化建设、提升次中心城市、重点发展中小城市、加快小城镇建设等方面着手对长株潭城市群等级规模结构进行优化。     

基于Kernel密度解释的江苏省城市规模结构演化研究

城市规模结构研究可以反映城市在不同规模等级中的分布状况及城市人口集聚或分散程度,有助于认识城市体系发展所处的阶段以及该区域城市化进程的特征。研究运用Kernel城市空间密度分析方法,直观的反映了江苏省城市规模分布格局的连续变化。分别从城市体系的空间格局、城镇密集带的结构变化和长三角城市群城镇网络构建等视角对城市规模结构进行探讨,指出全省城市规模空间分布的Kernel密度在整体上具有西高东低、南密北疏的态势;城市体系的空间模式由最初的核心-边缘结构,逐渐向点-轴-面结构演化;南京都市圈的进一步延伸,将促进长三角多核心巨型城市网络向更大地域范围拓展。由此提出全省在不断优化城市体系的同时,需要更加注重大中城市及小城镇协调发展机制的建设,加强对苏中、苏北地区城市人口规模的扩张和城市规模布局的均衡,建立具备完整城市功能的网络城市发展模式,以更好的促进区域一体化发展。     

Population,light, and the size distribution of cities

We provide new insights on the city size distribution of countries around the world. Using more than 10,000 cities delineated via geospatial data and a globally consistent city identification scheme, we investigate distributional shapes in all countries. In terms of population, we find that Zipf's law holds for many, but not all, countries. Contrasting the distribution of population with the distribution of economic activity, measured by nighttime lights, across cities we shed light on the globally variant magnitude of agglomeration economies. Deviations from Zipf's law are to a large extent driven by an undue concentration in the largest cities. They benefit from agglomeration effects which seem to work through area rather than through density. Examining the cross‐country heterogeneity in the city size distribution, our model selection approach suggests that historical factors play an important role, in line with the time of development hypothesis.     

The Dynamics of Growth in a Regional Urban System: Southern Ontario, 1851–1971

This study has four objectives: (1) to describe the dynamics of growth in the urban system of southern Ontario over the period from 1851 to 1971; (2) to determine whether this system has evolved in accordance with the Gibrat process of growth; (3) to contribute to the debate on the relationship between city-size distributions and economic development; and (4) to offer some technical and definitional suggestions with regard to the rank-size rule, urban primacy, and the measurement of population concentration. Related Canadian studies covering similar time periods are those of Simmons (1974), who has analysed the growth of larger cities (10,000 and over) at the national scale, and Bannister (1975), who has described the extent of spatial autocorrelation in the growth rates of southern Ontario's incorporated centres. Like Simmons and Bannister we are less concerned with the fortunes of particular places than with the response of the urban system as a whole to expansionary forces. We are centrally concerned with the phenomenon of differential growth (Borchert, 1967; Ward, 1971, pp. 11–49; Muller, 1976, 1977). The fact that towns grow at different rates implies changes in the frequency distribution of city size and in the level of concentration of the urban population. These changes, in turn, have interesting consequences for urban systems theory.     

吉林省城市体系等级规模结构研究

等级规模结构是城市体系的三大结构之一,其特征可以反映出城市在不同规模层次中的分布状况及城市人口集中或分散的程度,有助于认识城市体系发展所处的阶段。通过统计数据计算分析,运用分形理论,发现吉林省城市体系等级规模结构满足位序-规模分布规律,城市规模分布的均衡程度较高,中小城市比较发育,首位城市垄断作用不突出,缺乏大城市。在吉林省城市体系动态变化过程中,等级规模结构相对稳定且不断趋于集中。在此基础上提出重点培育通化、延吉等大城市;继续扩大长春规模,发挥整体效益;加强交通网络建设;加快矿业城市可持续发展等建议。     

On the Sources of Instability in the Rank-Size Rule: Some Simple Tests of Gibrat's Law

While the implications of the Simon model of urban growth, e.g., the rank-size rule, have been explored in numerous papers, the assumptions of that model have not, to my knowledge, been subjected to empirical verification. This paper represents an initial attempt to do so, emphasizing those sources of variation in the growth of cities typically singled out in Simon's verbal statements of the model: births, deaths, rural-urban, urban-rural, and urban-urban migration. It is found that over the recent past the assumptions concerning these components are all violated and violated in the direction of upward curvature away from the log-linear relationship between city size and rank predicted by the model, an upward curvature which we in fact observe.     

风险视角下的城市聚落形成模拟

幂次法则是普遍存在于自然科学和社会科学界的现象,而城市位序-规模法则是幂次法则在城市科学中的体现之一,然而特定城市规模分布一直缺乏完整的解释。本文尝试结合城市增长过程中土地开发行为的报酬递增规则与土地开发主体的风险认知行为,以城市增长的微观过程为切入视角模拟宏观城市聚落演化过程,进而探讨风险态度对城市聚落形态,尤其是对其规模分布的影响。研究结果表明：①即使城市聚落演化过程中存在多种风险态度,幂次法则在城市聚落的规模分布中仍保持着稳健性; ②现实世界中城市聚落规模分布的变异和稳定可能来自城市主体风险态度的多样性。     

Regional Concentration of the Knowledge-based Economy in the EU: Towards a Renewed Oligocentric Model?

This paper aims to contribute to a better understanding of the Knowledge-based Economy spatial distribution across the European Union (EU) regions (NUTS II), linking recent research approaches on innovation and structural change with approaches to regional economics. As a means of conducting this research, we classify economic activities according to six sectors based on their knowledge/technology intensity. Our results show that the higher the knowledge/technology content of the economic activity, the higher the concentration level of the activity. We find that some service activities (those considered knowledge intensive) have similar concentration levels to those operating in high or medium tech manufacturing. With regard to specialization, the most outstanding result is the strong presence of high and medium knowledge intensive service activities in metropolitan/capital regions. In general, our results reinforce the notion that an oligocentric model persists in Europe, with the southern German regions leading high and medium tech manufacturing, the south-east of England leading in high knowledge-intensive services, and with the mid-core model exemplified by the European metropolitan archipelago (particularly capital cities) in both northern and southern Europe.     

中国城市间交通流强度的空间格局

以全国321个地级以上行政区为研究对象,基于城市间汽车、火车和航空班次联系测算各城市对外联系强度,通过核密度估计、位序-规模及探索性空间数据分析,对多元交通流视角下城市间交通流强度的空间格局进行提取和解析。研究表明:在整个城市体系中,高位次城市规模凸显,中小规模城市有待于进一步发育。基于公路和铁路联系的城际交通流分别表现为由沿海向内陆逐级减弱、以国家铁路大动脉沿线为中心的核心-边缘结构;基于航空联系的城际交通流表现出高度极化和点状镶嵌特征。     

Elastic labor supply and agglomeration

This study analyzes the interplay between the agglomeration of economic activities and interregional differences in working hours, which are typically longer in large cities, as they are normally more developed than small cities. For this purpose, we develop a two‐region model with endogenous labor supply. Although we assume a symmetric distribution of immobile workers, the symmetric equilibrium breaks in the sense that firms may agglomerate when trade costs are intermediate and labor supply is elastic. We also show that the price index is always lower, while labor supply, per capita income, real wages, and welfare are always higher in the more agglomerated region.     

MANAGEMENT OF LARGE CITY REGIONS: DESIGNING EFFICIENT METROPOLITAN FISCAL POLICIES*

ABSTRACT Metropolitan areas (MSAs) are the location of the great majority of economic activity in the United States, and the largest produce a disproportionate share of output. It is thus critical for the economy's long‐term growth that large cities operate efficiently. In this paper, we briefly review the sources of productivity growth in cities. We then discuss the costs and benefits of political decentralization in large MSAs. After documenting the interdependence of the suburbs and central cities in large MSA, we develop a model that embodies many of the empirically verified aspects, including agglomeration economies and public goods. After calibrating the model to actual outcomes in a representative city, we simulate the effects of various kinds of fiscal redistributions. We conclude that, under the model, some kinds of fiscal redistributions can provide benefits in both cities and suburbs.     

武汉都市圈经济社会要素流的空间分析

都市圈城际经济联系与相互作用空间表现形式为城市间、城市-区域间的人流、物流、信息流、资金流、技术流等经济社会要素流。基于城际功能集散效应影响量建立城市流模型:F=NE,揭示出:武汉都市圈各中心城市经济社会要素流强度空间差异明显,对外经济联系呈现显著规模等级分布,空间结构上已经形成以武汉为中心的"鞍形"圈层结构。通过统计数据,利用SPSS统计软件,从实证角度分析得出:武汉成为圈域经济社会要素流集散中心,城际经济社会要素流不同程度表现出以武汉为中心的"等级放射状"空间格局。     

EVOLUTION OF URBAN SYSTEMS IN THE PARETO PLANE*

ABSTRACT Distributions of city sizes are usually characterized by their Pareto index. This, however, turns out to be a rather restrictive view, for the Pareto distribution is known to become singular whenever the Pareto index becomes smaller than one, a case which is fairly frequent in empirical distributions. We show that the introduction of finite Pareto distributions in which city sizes are bounded from above solves a number of difficulties encountered by the rank-size rule and by the unbounded Pareto distribution. Combined with the use of finite Pareto distributions, the green-belt model that has been introduced previously is reexamined. It implies definite constraints for the long-run evolution of urban systems; it is in the cases of countries experiencing a process of fast urbanization that these constraints are of greatest significance. The implications of the model are confronted with empirical evidence concerning the evolution of urban systems in major industrialized countries during the nineteenth and twentieth centuries.     

An Empirical Enquiry into the Impact of Urban Planning Policy on Urban Growth

Recent research has stressed the need to evaluate the economic implications of urban planning policy. In this article, we present empirical evidence on the impact of this policy on the population growth of towns and cities. A simple theoretical model serves to highlight the mechanisms whereby this policy may affect urban growth. The model yields a reduced-form equation which we estimate for the towns and cities of Andalusia (Spain). The empirical model strongly supports the claim that urban planning policy considerably affects urban growth and thus, the distribution of population across space. Our results suggest that urban planning policy is contributing to the reduction of diseconomies of agglomeration in larger cities. On the negative side, we find that urban plans are subject to obsolescence, which slows down growth.     

Gibrat Revisited: An Urban Growth Model Incorporating Spatial Interaction and Innovation Cycles. 再评吉尔布瑞特：顾及空间相互作用和创新周期的城市增长模型

We designed a geographical model for simulating the distribution of urban growth in systems of cities. The model incorporates the hierarchical and spatial diffusion of innovation cycles through gravitational interactions within a set of cities. Using theoretical simulations, we demonstrate that this model is able to reproduce the observed properties of urban systems for the log‐normal distribution of city sizes as well as the observed distribution of growth rates. Our experimentation was performed on a large harmonized historical database that includes a few hundred French urban agglomerations between 1831 and 1999 (Pumain‐INED database). Both spatial interaction and innovation cycles are necessary ingredients to explain the evolution of urban hierarchies. We suggest that Gibrat's generic stochastic growth model based on independent entities should be replaced by a more relevant model of spatially and temporally interdependent geographical entities.