Local governments have long been ardently pursuing the industrial specialization effect(MAR externalities) and industrial diversification effect(Jacobs externalities). Such a pursuit has resulted in severe distortion ...Local governments have long been ardently pursuing the industrial specialization effect(MAR externalities) and industrial diversification effect(Jacobs externalities). Such a pursuit has resulted in severe distortion of resource allocation and negative effect on sustainability of local economic development. Regarding the effect from both MAR and Jacobs externalities on local economic development existing literature records notable disputes. Therefore, for local economic development, one important issue is which externality(MAR or Jacobs) can better bring the effect into play. By studying a panel data of 283 Chinese cities from 2003 to 2012 and applying dynamic plane data GMM method, this paper conducted a regression analysis of the relationship among industrial agglomeration externalities, city size, and regional economic development. The result indicates that with regard to the whole nation, MAR externalities are conducive to regional economy development whereas Jacobs externalities will, to an extent, restrain regional economic development. As regards eastern, middle, and western regions, MAR externalities are conducive only to the economic development of the eastern region; their effects on middle and western regions are insignificant. Moreover, the interaction item between MAR externalities and city size has a significant negative synergistic effect on national economic development and a certain acceleration effect on eastern region as well as a strong negative synergistic effect on the middle region and an insignificant effect on the western region. The interaction item between Jacobs externalities and city size has a positive synergistic effect on only the middle region and has an insignificant synergistic effect on both eastern and western regions. Capital stock and labor input have significant accelerating effects on GDP growth per capita of Chinese cities, whereas material capital and labor input remain primary driving forces for Chinese local economic development. Furthermore, human capital contributes to accelerating urban economic development, whereas government intervention restrains urban economic development.展开更多
Economics literature has long overlooked an important economic phenomenon:Residents in large cities tend to save a smaller percentage of their disposable income than their peers in small and medium-sized cities.As an ...Economics literature has long overlooked an important economic phenomenon:Residents in large cities tend to save a smaller percentage of their disposable income than their peers in small and medium-sized cities.As an explanation for this phenomenon,this paper puts forth the hypothesis that:Residents in large cities purchase more services to increase their leisure time,which is reduced by longer commuting time than in small and medium-sized cities,thus lowering their household savings rate.We conducted an empirical study using panel data of China’s prefecture-level cities and urban household survey data,and employed an instrumental variable to address the endogeneity problem.The result confirmed the accuracy of the above hypothesis.In identifying the economic phenomenon and putting forth the hypothesis,this paper(i)creates a theoretical link between city size and household savings rate,which helps unravel the determinants of the urban household savings rate;(2)provides important implications for China’s policy-making on domestic consumption,urban populations,and industrial development.Priority should be given to developing large and medium-sized cities given the positive effects on domestic consumption and service sector development,and migrant labor shall not be barred from entering large and medium-sized cities to provide services to local residents.展开更多
China is experiencing rapid urbanization and motorization. Urban transport congestion poses a challenge to the cities of China. Policies have been made trying to control the car use and the land use in Chinese cities ...China is experiencing rapid urbanization and motorization. Urban transport congestion poses a challenge to the cities of China. Policies have been made trying to control the car use and the land use in Chinese cities without sound modelling researches. The existing literature on monocentric city modelling has shown that the parameters are critical for the outcome of the modelling. Following the Alonso-type monocentric model, this paper introduces a bi-modal model to simulate the city size, the distribution of land rent and the modal substitution in Chinese cities. We set the key parameters according to the recent available data of China′s cities, and re-explain the hypothesis of the model. Then we make a sensitivity analysis to reveal the impacts of key parameters on the Chinese cities. According to the results, we find that the wage, the price of car use and the agriculture rent have significant impacts on city size. The land supply for the private transport or the public transport has the strongest impacts on car use and the level of transport congestion. The total population of the city and the wage level have strong impacts on land rent. Some results are counter-intuitive, but explainable. We also discuss implication of these results for policy making.展开更多
City size distribution is of interest because of a number of key stylized facts, including notably Zipf's law for cities and the importance of urban primacy. But a new and more efficient method Gini index can be u...City size distribution is of interest because of a number of key stylized facts, including notably Zipf's law for cities and the importance of urban primacy. But a new and more efficient method Gini index can be used for calculating regional city size distribution. This paper begins by developing a calculation method for the Gini index, dividing the whole country into 26 areas and then calculating each area's Gini index value. Based on these calculation results, this paper gives a preliminary study on regional differences of its city size distribution and the dynamics.展开更多
Since the reform and opening up program was initiated in 1978,China’s urbanization has made rapid progress,but urban development remains unbalanced and insufficient.From the perspective of social and cultural diversi...Since the reform and opening up program was initiated in 1978,China’s urbanization has made rapid progress,but urban development remains unbalanced and insufficient.From the perspective of social and cultural diversity,this paper explores the impact of dialect diversity on city size.Dialect diversity impedes the expansion of cities by causing a trust segmentation and impeding cross-regional factor flow and the factor agglomeration effect.Based on the regional dialect diversity indicator and the NPP-VIIRS city night-time light index of 2016,this paper offers an empirical study of the impact of dialect diversity on city size.Econometric results indicate that dialect diversity has a significantly negative impact on city size.On average,an increase of each dialect sub-category leads to a decrease in city size estimated by the night-time light index by 4.55%.Robustness test and causality identification reveal that the estimated results of this paper have a robust causal relationship.Further empirical research indicates that dialect diversity affects the expansion of city size by inhibiting the flow and agglomeration of labor,capital and technology factors.Our research suggests that the development of diverse and inclusive modern cities needs to balance the costs and benefits of cultural diversity and uniformity,break through cultural barriers,remove cultural prejudices,raise the level of social trust,and give play to the complementary effect of cultural diversity.展开更多
This article explored China’s urban employment dynamics with particular focus on the city size effect.Big data derived from the largest recruitment website were used to examine the direct and indirect impacts of city...This article explored China’s urban employment dynamics with particular focus on the city size effect.Big data derived from the largest recruitment website were used to examine the direct and indirect impacts of city size on employment demand by using mediating and moderating models.We also investigated the roles of the government and location factors which have seldom been considered in literature.Results showed that the concentration degree of new jobs is higher than that of stock employment and population across cities,implying a path dependency mechanism of job creation and employment expansion.Meanwhile,numerous job posts in inland central cities are probably a symptom of more even distribution of employment in future China.Econometric models further verified the significant correlation between city size and job creation.Moreover,industrial diversity,fixed asset investment,and spatial location have heterogeneous effects on employment demand in cities of different sizes and different levels of administration.These results can not only deepen our understanding of the crucial role of city size in urban employment growth but also demonstrate the future trend of labor and population geography of China.Policy implications are then proposed for job creation in cities of China and other developing countries.展开更多
Nowadays more and more people reside in metropolitan areas,and the impact of this phenomenon is clearly creating challenges for the environment,the economy and the society at large.It is therefore useful and instructi...Nowadays more and more people reside in metropolitan areas,and the impact of this phenomenon is clearly creating challenges for the environment,the economy and the society at large.It is therefore useful and instructive to consider the issue of optimal city size and review the literature over the past decades on optimal city size theory.Based on the progress in recent years of comparative analysis and inductive research,from both theoretical and empirical perspectives,this paper outlines the original definitions proposed for optimal city size and discusses some of the advantages and disadvantages of the various theories.The two prevailing models in the classical analysis of optimal city size,the Henry George Theorem(HGT)and the neoclassical approach,are examined later.This paper then introduces the supply oriented dynamic model(SOUDY model)and offers a plausible model for optimal city size based on the general equilibrium analysis,which is related to sustainable development.The results show that:(1)Simple optimal city size theories come from the cost-benefit analysis developed by main stream economics,and therefore cannot overcome the defect that the optimal size of cities is the same since the same production function;(2)The Henry George Theorem,which is one of the classical analysis paradigms of optimal city size,has been used more frequently in recent years to research the issues of optimal tax and public goods and has gradually lost its connection to the topic of optimal city size;(3)The neoclassical approach to optimal city size consists of externalities influencing optimal city size,the equilibrium and optimal models for city size,the optimal town,product variety and city size distribution.This kind of research is still in the mainstream of the study of optimal city size.Compared to single optimal city size,more attention is paid to the optimal distribution of city size;and(4)The supply-oriented dynamic model allows for the integration of a spatial dimension into the economic research of optimal city size,and the constraint between city level and city size is relaxed and this has more power to explain real-world problems.At the same time,the general equilibrium analysis,as a significant economic research method,provides a new perspective for the study of optimal city size.The supply-oriented dynamic model and general equilibrium analysis are two new research paradigms that deserve more attention in the analysis of optimal city size.展开更多
The optimal city size has always been a heated topic for debate in China. Given the background of global warming and fossil fuel crisis, it is argued that the issue should be considered from not only the perspective o...The optimal city size has always been a heated topic for debate in China. Given the background of global warming and fossil fuel crisis, it is argued that the issue should be considered from not only the perspective of economic benefits of a city but should also consider the energy consumption efficiency of the city. On the basis of the energy consumption data of 286 cities at the prefectural level and above in Chinese mainland except Lasa, which are obtained from the EU Emission Database for Global Atmospheric Research(EDGAR), this paper carries out an empirical analysis on the relationship between the city size and the energy consumption efficiency of the city. Then based on this analysis, the paper further examines the economic benefits, social benefits, and environment quality of cities in different scales, and the findings reveal that large cities with 2 – 5 million population have the highest efficiency in all these aspects.展开更多
Without a clear and unified definition of the urban built-up area, many city rankings by area are inconsistent, giving rise to confusion among the general public and even scholars. This paper summarizes various defini...Without a clear and unified definition of the urban built-up area, many city rankings by area are inconsistent, giving rise to confusion among the general public and even scholars. This paper summarizes various definitions of the urban built-up area and proposes three definition methods: all urban built-up areas in a municipal administrative area, concentrated contiguous built-up areas, and urban built-up areas in central cities. From the latest Landsat 8 satellite images, the paper obtains the data of urban built-up area in some of China’s big cities and makes a comparative study between the results of the urban built-up areas by the three definition methods and three other common statistical data. It finds that neither the area data nor the ranking is consistent. Finally, it further explores what causes differences in rankings and gives some advice for improving the definition of the urban built-up area.展开更多
Dispersed and peripheral spaces in the urban core are influenced both by the trend towards constant growth as well as social ways of life which are constantly evolving. Following a connotation, these two factors there...Dispersed and peripheral spaces in the urban core are influenced both by the trend towards constant growth as well as social ways of life which are constantly evolving. Following a connotation, these two factors therefore play a crucial role in defining the alternation of urban space--in particular, that of the centers. The main focus of this research article is on the methodology used in the survey and evaluation of "centralities" as well as their developments over the past four decades (1974-2014) in approaches to urban development that has been developed in Graz.~ The analysis has drawn on the four editions ("evolution") of approaches to urban development as conceived by the city of Graz in order to examine their verbal characteristics in regard to centralities. At the same time, the analysis does not examine presentations of plans which exist in supplementary forms (e.g., explanatory reports and supplemented plans)--it restricts itself solely to the various plans set out in the STEKs.2 The highest degree of accuracy has been applied to the notion of "centralis" in approaches to urban development. The goal of the research project was to depict the modulation of the notion of "centrality" in the urban context as a space-forming dimension. Furthermore, it clearly shows the extent to which the notion of the "centre" (in the widest sense of the word) has become distanced from qualitative, spatial development and at the current time of urban development is experiencing a sort of Renaissance. In the field of "urban development", architectural references in the context of"centrality" have scarcely been researched. This has led to the opening-up of a complex interdisciplinary research field. In order to make the complex architectural determinants of "centrality" more accessible to the participating disciplines, approaches to urban development have been explored in the form of a social and spatial analysis.展开更多
Ecological city(eco-city) and its planning approach are emerging concepts in urban study,urban planning,ecological economics,environmental policy and corporate environmental management.However,opinions remain divided ...Ecological city(eco-city) and its planning approach are emerging concepts in urban study,urban planning,ecological economics,environmental policy and corporate environmental management.However,opinions remain divided over the connotation and denotation of the term"ecological city",what key issues ecocity planning can solve,and its specific contents.In this study,we present 10 basic propositions that define the eco-city and clarify its key parameters,thereby providing the basis for discussing the assumptions and principles underlying different approaches to sustainable urban development.We then summarize the concept and principles of an eco-city,and define the main requirements for ecocity planning.We conclude that an eco-city is a city in which the urban population,scale of land use and intensity of human activities are limited to the regional resource and environmental carrying capacity,which does not cause increasing or irreversible damage to the regional ecosystem's structure,functions and processes.展开更多
City growth patterns are attracting more attention in urban geography studies. This paper examines how cities develop and grow in the upper tail of size distribution in a large-scale economy based on a theoretical mod...City growth patterns are attracting more attention in urban geography studies. This paper examines how cities develop and grow in the upper tail of size distribution in a large-scale economy based on a theoretical model under new economic geography framework and the empirical evidence from the US. The results show that cities grow in a sequential pattern. Cities with the best economic conditions are the first to grow fastest until they reach a critical size, then their growth rates slow down and the smaller cities farther down in the urban hierarchy become the fastest-growing ones in sequence. This paper also reveals three related features of urban system. First, the city size distribution evolves from low-level balanced to primate and finally high-level balanced pattern in an inverted U-shaped path. Second, there exist persistent discontinuities, or gaps, between city size classes. Third, city size in the upper tail exhibits conditional convergence characteristics. This paper could not only contribute to enhancing the understanding of urbanization process and city size distribution dynamics, but also be widely used in making effective policies and scientific urban planning.展开更多
Based on the significant difference of China’s cities at different(administrative)hierarchical levels in population growth over the past three decades,this study explains the influence of urban development policies(i...Based on the significant difference of China’s cities at different(administrative)hierarchical levels in population growth over the past three decades,this study explains the influence of urban development policies(industrial policies and land policies)on the gap in urban population growth from the perspective of government favoritism.Taking 423 cities during 1990-2015 as samples,this paper selects two indicators,setting up national development zones and turning counties into districts,to represent government favoritism and applies the PSM-DID method.The empirical result shows government favoritism in setting up national development zones and turning counties into districts is conducive to urban population growth and helps generate synergy effects of industrial and land policies.Market potential of cities is an important condition for the effect of government favoritism.The result fi nds that government favors higher-level cities and coastal ones,but overlooks inland medium-and low-level cities,resulting in the shallow U-shaped characteristics of“higher on both ends and lower in the middle”in population growth of cities at different levels.In order to prevent inland medium-and low-level cities from“collapsing”relatively,the government should break its favoritism for high-level cities,transform industrial and land policies from“preference system”to“generalized system of preference”,and put greater favor of inland medium-and low-level cities with certain market potential.展开更多
Number concentrations and distributions of 10-10,000 nm particles in a large city (Jinan) in the North China Plain were measured in winter 2009. The mean number concentrations of nucleation mode (10-20 nm), Aitken...Number concentrations and distributions of 10-10,000 nm particles in a large city (Jinan) in the North China Plain were measured in winter 2009. The mean number concentrations of nucleation mode (10-20 nm), Aitken mode (20-100 nm), and accumulation mode (100-1000 nm) particles, as well as total particles were 925, 6898, 2476, and 10,299cm-3, respectively. Two severe haze episodes, with elevated concentrations caused by pollutants accumulating, were observed. Accumulation mode particle concen- trations were significantly higher during the episodes than on clear days, and nucleation mode particle concentrations were pronouncedly higher on clear days than during the episodes. The peaks of domi- nant number, surface area, and mass size distributions were around 30-50, 200-300, and 200-400 rim, respectively, both during the haze episodes and on clear days, but elevated mass and surface area con- centrations around 500-600 nm were also observed during the haze episodes, suggesting these particles had significant contributions to haze formation. These particles were probably formed through larger droplets in cloud and fog evaporating. Two new particle formation events, probably triggered by strong photochemical processes on clear days and significant traffic emissions during haze episode 2, were found. Significant insights were made into haze formation in a oolluted Chinese urban area.展开更多
Currently, there are controversies onthe development policy for large, mediumand small sized cities. To appraise the ad-vantages and disadvantages of cities of vari-ous sizes from different angles, conclusionscan vary...Currently, there are controversies onthe development policy for large, mediumand small sized cities. To appraise the ad-vantages and disadvantages of cities of vari-ous sizes from different angles, conclusionscan vary tremendously. Starting from devel-opment productivity, cities in China shouldaim at achieving good output returns. This article tries to discuss the outputreturns of cities of different size from展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41571112)Natural Science Foundation of Zhejiang Province of China(No.LY16D010002)
文摘Local governments have long been ardently pursuing the industrial specialization effect(MAR externalities) and industrial diversification effect(Jacobs externalities). Such a pursuit has resulted in severe distortion of resource allocation and negative effect on sustainability of local economic development. Regarding the effect from both MAR and Jacobs externalities on local economic development existing literature records notable disputes. Therefore, for local economic development, one important issue is which externality(MAR or Jacobs) can better bring the effect into play. By studying a panel data of 283 Chinese cities from 2003 to 2012 and applying dynamic plane data GMM method, this paper conducted a regression analysis of the relationship among industrial agglomeration externalities, city size, and regional economic development. The result indicates that with regard to the whole nation, MAR externalities are conducive to regional economy development whereas Jacobs externalities will, to an extent, restrain regional economic development. As regards eastern, middle, and western regions, MAR externalities are conducive only to the economic development of the eastern region; their effects on middle and western regions are insignificant. Moreover, the interaction item between MAR externalities and city size has a significant negative synergistic effect on national economic development and a certain acceleration effect on eastern region as well as a strong negative synergistic effect on the middle region and an insignificant effect on the western region. The interaction item between Jacobs externalities and city size has a positive synergistic effect on only the middle region and has an insignificant synergistic effect on both eastern and western regions. Capital stock and labor input have significant accelerating effects on GDP growth per capita of Chinese cities, whereas material capital and labor input remain primary driving forces for Chinese local economic development. Furthermore, human capital contributes to accelerating urban economic development, whereas government intervention restrains urban economic development.
基金This paper is a result of the major program of the Key Research Base for Humanities and Social Sciences of the Ministry of Education“Structural Transition,Urban Development and China’s Economic Growth”(Grant No.17JJD790005)sponsorships from the National Natural Science Foundation of China(NSFC)(Grant No.71841008,71833003,71863001)the Peak Program for Theoretical Economics at Fudan University。
文摘Economics literature has long overlooked an important economic phenomenon:Residents in large cities tend to save a smaller percentage of their disposable income than their peers in small and medium-sized cities.As an explanation for this phenomenon,this paper puts forth the hypothesis that:Residents in large cities purchase more services to increase their leisure time,which is reduced by longer commuting time than in small and medium-sized cities,thus lowering their household savings rate.We conducted an empirical study using panel data of China’s prefecture-level cities and urban household survey data,and employed an instrumental variable to address the endogeneity problem.The result confirmed the accuracy of the above hypothesis.In identifying the economic phenomenon and putting forth the hypothesis,this paper(i)creates a theoretical link between city size and household savings rate,which helps unravel the determinants of the urban household savings rate;(2)provides important implications for China’s policy-making on domestic consumption,urban populations,and industrial development.Priority should be given to developing large and medium-sized cities given the positive effects on domestic consumption and service sector development,and migrant labor shall not be barred from entering large and medium-sized cities to provide services to local residents.
基金Under the auspices of National Science and Technology Support Program of China(No.2012BAJ22B05)National Natural Science Foundation of China(No.41401170)
文摘China is experiencing rapid urbanization and motorization. Urban transport congestion poses a challenge to the cities of China. Policies have been made trying to control the car use and the land use in Chinese cities without sound modelling researches. The existing literature on monocentric city modelling has shown that the parameters are critical for the outcome of the modelling. Following the Alonso-type monocentric model, this paper introduces a bi-modal model to simulate the city size, the distribution of land rent and the modal substitution in Chinese cities. We set the key parameters according to the recent available data of China′s cities, and re-explain the hypothesis of the model. Then we make a sensitivity analysis to reveal the impacts of key parameters on the Chinese cities. According to the results, we find that the wage, the price of car use and the agriculture rent have significant impacts on city size. The land supply for the private transport or the public transport has the strongest impacts on car use and the level of transport congestion. The total population of the city and the wage level have strong impacts on land rent. Some results are counter-intuitive, but explainable. We also discuss implication of these results for policy making.
文摘City size distribution is of interest because of a number of key stylized facts, including notably Zipf's law for cities and the importance of urban primacy. But a new and more efficient method Gini index can be used for calculating regional city size distribution. This paper begins by developing a calculation method for the Gini index, dividing the whole country into 26 areas and then calculating each area's Gini index value. Based on these calculation results, this paper gives a preliminary study on regional differences of its city size distribution and the dynamics.
基金Chongqing University Innovation Capacity Improvement Program“Cross-Jurisdictional Coordinated Development and Governance of Contiguous Poor Regions”(Grant No.2019CDSKXYGG0043)Chongqing University Fundamental Research Funds Program for the Central Universities“Regional Differences of Social Trust Modes and the Economic Effects”(Grant No.2018CDJSK01XK06).
文摘Since the reform and opening up program was initiated in 1978,China’s urbanization has made rapid progress,but urban development remains unbalanced and insufficient.From the perspective of social and cultural diversity,this paper explores the impact of dialect diversity on city size.Dialect diversity impedes the expansion of cities by causing a trust segmentation and impeding cross-regional factor flow and the factor agglomeration effect.Based on the regional dialect diversity indicator and the NPP-VIIRS city night-time light index of 2016,this paper offers an empirical study of the impact of dialect diversity on city size.Econometric results indicate that dialect diversity has a significantly negative impact on city size.On average,an increase of each dialect sub-category leads to a decrease in city size estimated by the night-time light index by 4.55%.Robustness test and causality identification reveal that the estimated results of this paper have a robust causal relationship.Further empirical research indicates that dialect diversity affects the expansion of city size by inhibiting the flow and agglomeration of labor,capital and technology factors.Our research suggests that the development of diverse and inclusive modern cities needs to balance the costs and benefits of cultural diversity and uniformity,break through cultural barriers,remove cultural prejudices,raise the level of social trust,and give play to the complementary effect of cultural diversity.
基金Major Project of National Social Sciences Foundation of China,No.20&ZD173。
文摘This article explored China’s urban employment dynamics with particular focus on the city size effect.Big data derived from the largest recruitment website were used to examine the direct and indirect impacts of city size on employment demand by using mediating and moderating models.We also investigated the roles of the government and location factors which have seldom been considered in literature.Results showed that the concentration degree of new jobs is higher than that of stock employment and population across cities,implying a path dependency mechanism of job creation and employment expansion.Meanwhile,numerous job posts in inland central cities are probably a symptom of more even distribution of employment in future China.Econometric models further verified the significant correlation between city size and job creation.Moreover,industrial diversity,fixed asset investment,and spatial location have heterogeneous effects on employment demand in cities of different sizes and different levels of administration.These results can not only deepen our understanding of the crucial role of city size in urban employment growth but also demonstrate the future trend of labor and population geography of China.Policy implications are then proposed for job creation in cities of China and other developing countries.
基金The Scientific Research Project of Hunan Education Department(18C0964)The 2016 Scientific Research Fund Project for Young Teachers of Hunan University of Finance and Economics(Q201604)
文摘Nowadays more and more people reside in metropolitan areas,and the impact of this phenomenon is clearly creating challenges for the environment,the economy and the society at large.It is therefore useful and instructive to consider the issue of optimal city size and review the literature over the past decades on optimal city size theory.Based on the progress in recent years of comparative analysis and inductive research,from both theoretical and empirical perspectives,this paper outlines the original definitions proposed for optimal city size and discusses some of the advantages and disadvantages of the various theories.The two prevailing models in the classical analysis of optimal city size,the Henry George Theorem(HGT)and the neoclassical approach,are examined later.This paper then introduces the supply oriented dynamic model(SOUDY model)and offers a plausible model for optimal city size based on the general equilibrium analysis,which is related to sustainable development.The results show that:(1)Simple optimal city size theories come from the cost-benefit analysis developed by main stream economics,and therefore cannot overcome the defect that the optimal size of cities is the same since the same production function;(2)The Henry George Theorem,which is one of the classical analysis paradigms of optimal city size,has been used more frequently in recent years to research the issues of optimal tax and public goods and has gradually lost its connection to the topic of optimal city size;(3)The neoclassical approach to optimal city size consists of externalities influencing optimal city size,the equilibrium and optimal models for city size,the optimal town,product variety and city size distribution.This kind of research is still in the mainstream of the study of optimal city size.Compared to single optimal city size,more attention is paid to the optimal distribution of city size;and(4)The supply-oriented dynamic model allows for the integration of a spatial dimension into the economic research of optimal city size,and the constraint between city level and city size is relaxed and this has more power to explain real-world problems.At the same time,the general equilibrium analysis,as a significant economic research method,provides a new perspective for the study of optimal city size.The supply-oriented dynamic model and general equilibrium analysis are two new research paradigms that deserve more attention in the analysis of optimal city size.
文摘The optimal city size has always been a heated topic for debate in China. Given the background of global warming and fossil fuel crisis, it is argued that the issue should be considered from not only the perspective of economic benefits of a city but should also consider the energy consumption efficiency of the city. On the basis of the energy consumption data of 286 cities at the prefectural level and above in Chinese mainland except Lasa, which are obtained from the EU Emission Database for Global Atmospheric Research(EDGAR), this paper carries out an empirical analysis on the relationship between the city size and the energy consumption efficiency of the city. Then based on this analysis, the paper further examines the economic benefits, social benefits, and environment quality of cities in different scales, and the findings reveal that large cities with 2 – 5 million population have the highest efficiency in all these aspects.
文摘Without a clear and unified definition of the urban built-up area, many city rankings by area are inconsistent, giving rise to confusion among the general public and even scholars. This paper summarizes various definitions of the urban built-up area and proposes three definition methods: all urban built-up areas in a municipal administrative area, concentrated contiguous built-up areas, and urban built-up areas in central cities. From the latest Landsat 8 satellite images, the paper obtains the data of urban built-up area in some of China’s big cities and makes a comparative study between the results of the urban built-up areas by the three definition methods and three other common statistical data. It finds that neither the area data nor the ranking is consistent. Finally, it further explores what causes differences in rankings and gives some advice for improving the definition of the urban built-up area.
文摘Dispersed and peripheral spaces in the urban core are influenced both by the trend towards constant growth as well as social ways of life which are constantly evolving. Following a connotation, these two factors therefore play a crucial role in defining the alternation of urban space--in particular, that of the centers. The main focus of this research article is on the methodology used in the survey and evaluation of "centralities" as well as their developments over the past four decades (1974-2014) in approaches to urban development that has been developed in Graz.~ The analysis has drawn on the four editions ("evolution") of approaches to urban development as conceived by the city of Graz in order to examine their verbal characteristics in regard to centralities. At the same time, the analysis does not examine presentations of plans which exist in supplementary forms (e.g., explanatory reports and supplemented plans)--it restricts itself solely to the various plans set out in the STEKs.2 The highest degree of accuracy has been applied to the notion of "centralis" in approaches to urban development. The goal of the research project was to depict the modulation of the notion of "centrality" in the urban context as a space-forming dimension. Furthermore, it clearly shows the extent to which the notion of the "centre" (in the widest sense of the word) has become distanced from qualitative, spatial development and at the current time of urban development is experiencing a sort of Renaissance. In the field of "urban development", architectural references in the context of"centrality" have scarcely been researched. This has led to the opening-up of a complex interdisciplinary research field. In order to make the complex architectural determinants of "centrality" more accessible to the participating disciplines, approaches to urban development have been explored in the form of a social and spatial analysis.
基金supported by the Knowledge Innovation Project of Chinese Academy of Sciences (grant no. KZCX2-YW-422)
文摘Ecological city(eco-city) and its planning approach are emerging concepts in urban study,urban planning,ecological economics,environmental policy and corporate environmental management.However,opinions remain divided over the connotation and denotation of the term"ecological city",what key issues ecocity planning can solve,and its specific contents.In this study,we present 10 basic propositions that define the eco-city and clarify its key parameters,thereby providing the basis for discussing the assumptions and principles underlying different approaches to sustainable urban development.We then summarize the concept and principles of an eco-city,and define the main requirements for ecocity planning.We conclude that an eco-city is a city in which the urban population,scale of land use and intensity of human activities are limited to the regional resource and environmental carrying capacity,which does not cause increasing or irreversible damage to the regional ecosystem's structure,functions and processes.
基金National Natural Science Foundation of China,No.41230632 Key Project for the Strategic Science Plan in IGSNRR,CAS,No.2012ZD006
文摘City growth patterns are attracting more attention in urban geography studies. This paper examines how cities develop and grow in the upper tail of size distribution in a large-scale economy based on a theoretical model under new economic geography framework and the empirical evidence from the US. The results show that cities grow in a sequential pattern. Cities with the best economic conditions are the first to grow fastest until they reach a critical size, then their growth rates slow down and the smaller cities farther down in the urban hierarchy become the fastest-growing ones in sequence. This paper also reveals three related features of urban system. First, the city size distribution evolves from low-level balanced to primate and finally high-level balanced pattern in an inverted U-shaped path. Second, there exist persistent discontinuities, or gaps, between city size classes. Third, city size in the upper tail exhibits conditional convergence characteristics. This paper could not only contribute to enhancing the understanding of urbanization process and city size distribution dynamics, but also be widely used in making effective policies and scientific urban planning.
基金the General Program of National Natural Science Foundation of China“Research on the Coordinated Development of Chinese Urban System:Measurement,Causes and Performance Evaluation”(71873062)Major Program of National Social Science Foundation of China“Research on the Mechanism Design and Path Selection for Replacing Old Growth Drivers with New Ones”(18ZDA077).
文摘Based on the significant difference of China’s cities at different(administrative)hierarchical levels in population growth over the past three decades,this study explains the influence of urban development policies(industrial policies and land policies)on the gap in urban population growth from the perspective of government favoritism.Taking 423 cities during 1990-2015 as samples,this paper selects two indicators,setting up national development zones and turning counties into districts,to represent government favoritism and applies the PSM-DID method.The empirical result shows government favoritism in setting up national development zones and turning counties into districts is conducive to urban population growth and helps generate synergy effects of industrial and land policies.Market potential of cities is an important condition for the effect of government favoritism.The result fi nds that government favors higher-level cities and coastal ones,but overlooks inland medium-and low-level cities,resulting in the shallow U-shaped characteristics of“higher on both ends and lower in the middle”in population growth of cities at different levels.In order to prevent inland medium-and low-level cities from“collapsing”relatively,the government should break its favoritism for high-level cities,transform industrial and land policies from“preference system”to“generalized system of preference”,and put greater favor of inland medium-and low-level cities with certain market potential.
基金The authors gratefully acknowledge the NOAA Air Resources Laboratory for providing the HYSPLIT transport and dispersion model and access to the READY website (httP:nready.arl.noaa. gov), which were used in this study. The authors also acknowledge support provided by the Shandong Province Natural Science Foun- dation (ZR2010DQ022), the Independent Innovation Foundation of Shandong University (2012TS041), a China Postdoctoral Science Foundation funded project (20060400982), and the Shandong Post~ doctoral Science Innovation Foundation (200601003).
文摘Number concentrations and distributions of 10-10,000 nm particles in a large city (Jinan) in the North China Plain were measured in winter 2009. The mean number concentrations of nucleation mode (10-20 nm), Aitken mode (20-100 nm), and accumulation mode (100-1000 nm) particles, as well as total particles were 925, 6898, 2476, and 10,299cm-3, respectively. Two severe haze episodes, with elevated concentrations caused by pollutants accumulating, were observed. Accumulation mode particle concen- trations were significantly higher during the episodes than on clear days, and nucleation mode particle concentrations were pronouncedly higher on clear days than during the episodes. The peaks of domi- nant number, surface area, and mass size distributions were around 30-50, 200-300, and 200-400 rim, respectively, both during the haze episodes and on clear days, but elevated mass and surface area con- centrations around 500-600 nm were also observed during the haze episodes, suggesting these particles had significant contributions to haze formation. These particles were probably formed through larger droplets in cloud and fog evaporating. Two new particle formation events, probably triggered by strong photochemical processes on clear days and significant traffic emissions during haze episode 2, were found. Significant insights were made into haze formation in a oolluted Chinese urban area.
文摘Currently, there are controversies onthe development policy for large, mediumand small sized cities. To appraise the ad-vantages and disadvantages of cities of vari-ous sizes from different angles, conclusionscan vary tremendously. Starting from devel-opment productivity, cities in China shouldaim at achieving good output returns. This article tries to discuss the outputreturns of cities of different size from