Small and medium-sized cities have played important roles in China's new urbanization strategies. Small and medium-sized cities can not only help large cities avert over-concentration of population，but also avoid excessively decentralized rural industrialization in small towns. To develop small and medium-sized cities，characteristic industries and vocational education are required so that people can get employed in the cities and become residents easily. City infrastructure and public services are necessary for urban residents. Public-Private Partnership (PPP) may solve the problems of fund shortage that the local government is facing during the construction. Besides，supply system of accommodations should be modernized to help the rural-urban migration's dream of being settled down come true.

发展更多中小城市，提升中小城市的竞争力和吸引力是我国均衡城镇化战略的重要组成部分。文章旨在讨论发展中小城市的战略意义与对策，认为发展中小城市能有效破解“半城镇化”难题，推进转移人口市民化，有助于实现农民工的就地城镇化与我国区域间协调发展。当前发展中小城市，实现农民工市民化，既要把中小城市建立在坚实的产业基础上，完善创业扶持体系和职业培训体系，提升中小城市对转移人口的吸引力，实现就地城镇化;又要创新公共私营合作机制，解决中小城市在公共服务和基础设施建设中的资金瓶颈问题，并构建多渠道的房屋供给体系，实现落户中小城市居民的“安居梦”。

Urban agglomeration refers to a highly integrated city and town group. It comes into being with the development of industrialization and urbanization to the advanced stage. The formation and development of urban agglomeration is a long natural process, which is transformed from competition to cooperation. China is in a new stage of urbanization transition, and has entered a new era of leading the global urban agglomeration development in the 21st century. The research and experience model of China's urban agglomeration has been accepted by global urban agglomeration construction as reference. In this paper, the natural law of urban agglomeration is proposed, including developmental gradual law, multi-scale transmission law of space intensive utilization, the combination law of spatial crystal structure, the natural growth of the breeding tree, and the gradient upgrade law of sustainable development. Following these laws, Chinese geographers have made great contributions to the research and development of China's urban agglomerations, which focuses on academic theory, technical method, decision support and planning practice. We developed and scientifically defined the concept of urban agglomeration, and first adopted the identification standard of urban agglomeration space. We established the spatial intensive development and layout simulation decision support technology chain in urban agglomeration, and developed related software chain. We laid out the new pattern of 5+9+6 in the spatial organization of China's urban agglomerations, and formulated the first China's urban agglomeration planning technical regulation. We completed the development plan of most urban agglomerations in China, which has become an important basis for decision-making at the national level. In the future, geographers will play a growing role and shoulder the responsibility in the development of Chinese urban agglomerations. We should combine qualitative and quantitative methods, and use big data and intelligent decision support technology to solve a series of problems in the development of this cause. Only in this way can Chinese geographers make greater contributions to the development of urban agglomerations.

城市群是国家工业化和城镇化发展到高级阶段的产物,是高度一体化和同城化的城市群体,城市群形成发育过程是一个各城市之间由竞争变为竞合的漫长自然过程,遵循自然发展规律。中国正处在新型城镇化转型发展的新阶段,已进入21世纪引领全球城市群发展的新时代,中国城市群研究与建设的经验模式正在被全球城市群建设所效仿和借鉴。本文从理论上梳理并提出了城市群形成发育遵循的自然规律,包括城市群形成发育的阶段性规律、城市群多尺度空间集约利用传导规律、城市群空间晶体结构组合规律、城市群自然生长的育树成林规律和城市群可持续发展的梯度爬升规律。地理学家遵循这些发展规律,从学术理论、技术方法、决策支持和规划实践等方面为中国城市群的研究和发展做出了不可替代的重大贡献,主要包括提出并科学界定了城市群概念,提出了城市群空间范围的识别标准,创建了城市群空间集约拓展与布局仿真决策支持技术链,研制了城市群空间集约拓展与布局仿真决策支持系统软件链,提出了中国城市群空间组织的“5+9+6”新格局,研制出国内第一部《城市群规划技术规程》,编制完成了全国多数城市群发展规划,转化为国家决策的重要依据。未来中国城市群的发展与研究中,地理学家发挥作用的空间越来越大,地理学家肩负着不可推卸的责任使命,应责无旁贷地采用定性与定量相结合的研究方法,引用大数据、智能决策支持技术等新手段解决城市群发展面临的一系列问题,一如既往地为城市群发展吸纳众智、献计献策,发挥更大作用,做出更大贡献。

Promoting coordinated development among large, medium-sized, and small cities as well as small towns, is highly emphasized in Chinese National New Urbanization Plan. Therefore, it is of great significance to clarify the spatial interactions between cities from different hierarchies, and to confirm whether large cities are really conducive to the economic growth of small cities. However, previous empirical literatures mainly focused on the spatial spillover effect between cities from the same hierarchy, and neglected the heterogeneity of urban hierarchy. Furthermore, the sample of previous studies generally included all the provinces or prefecture cities in China, which led to the lack of exploration on the internal spatial interactions within urban agglomerations such as the Yangtze River Delta. Taking 108 small cities in the Yangtze River Delta as study samples, this paper examines the spatial spillover effects between cities from both same and different hierarchies, by adding geographical distance to different-hierarchy cities, whether within administrative boundary or not and market potentials into classic economic growth model. It is found that approaching large cities may contribute to the economic growth of small cities, and the agglomeration shadow hypothesized by the New Economic Geography is not supported in the Yangtze River Delta. This also means the economic growth of small cities is still under the influence of metropolitan areas, which demonstrates the necessity and benefits of metropolitan development strategy. Secondly, spatial interactions are more likely to happen between high- and low-hierarchy cities, whereas those between same hierarchy cities are relatively weak. The positive growth spillover effect from sub-provincial city on small cities is found to be most significant. Thirdly, the market segmentation caused by administrative boundaries weakens the spatial spillover effect. The small cities under the administrative jurisdiction of the nearest prefecture city receive lower economic growth rate than those beyond the administrative boundary of their nearest prefecture city. Finally, policy implications are put forward on how to make use of spatial spillover effect and promote the coordinated development among large, medium-sized, and small cities as well as small towns. The first and foremost is to strengthen the radiation and impetus function of large cities. Considering the urban hierarchy heterogeneity of spatial interaction and breaking market segmentation caused by administrative boundaries are of great urgency as well.

厘清大城市是否有利于小城市经济增长这一问题,对于贯彻大中小城市和小城镇协调发展的国家新型城镇化战略具有重要意义。以长三角108个小城市为例,在传统经济增长模型中加入到大城市的地理距离、行政边界、市场潜能等因素,估计不同等级的大城市对小城市经济增长的空间影响及其异质性。研究发现：临近大城市有助于促进小城市的经济增长,并未发现存在集聚阴影效应的直接证据;空间相互作用的方向更多体现为高等级城市对低等级城市的影响,来自副省级城市的增长溢出最为显著,同层级小城市之间的空间关联效应相对微弱;城市间存在一定程度的市场分割,行政边界的存在阻碍了空间溢出效应的发挥。最后从强化中心城市的辐射带动功能、促进不同规模城市空间溢出效应的全域性释放、破除行政区经济的束缚等方面提出了促进大中小城市和小城镇协调发展的政策启示。

In the context of the integrated development of Beijing-Tianjin-Hebei (BTH) region as a national strategy and the construction of Xiongan New Area, it is necessary to analyze the relationship of economic growth between large cities and small cities in this region. This paper examines the existence of "agglomeration shadow" and the "poverty belt around Beijing and Tianjin" suggested by the Asian Development Bank in 2005. The previous research of the "poverty belt around Beijing and Tianjin" did not conduct systematic analyses and empirical tests from the perspective of spatial interactions. The literature on spatial interactions has not reached an agreement on whether large cities are conducive to the economic growth of small cities. This paper aims to provide academic evidence for the coordinated development of the BTH region. The results reveal that the core cities in this region did curb the economic growth of small cities around them, supporting the "agglomeration shadow" proposed by new economic geography and the phenomenon "poverty belt around Beijing and Tianjin". Negative spillovers of economic growth exist among small cities as well, which could be attributed to the cut-throat competitions among small cities owing to the urgent desire for economic development of local governments. Compared with the Yangtze River Delta region where core cities benefit the economic growth of their adjacent cities, the radiating function and the trickle-down effect of core cities within the BTH region are obviously weak, and the development gap between large and small cities is greater. These conclusions indicate that to a great degree, the harmonious development of the BTH region is related to the radiation effects of the large cities, and the "agglomeration shadow" should be transformed into a sunshine zone of economic growth. In other words, a polycentric and reasonable urban hierarchy is crucial. From this point of view, the construction of the Xiongan New Area, as an anti-magnetic center just meets the need. This strategy will not only ease the pressure on Beijing, but also provide a new growth pole which helps to benefit the balance of regional economic growth and improve the "poverty belt around Beijing and Tianjin". The policy implications include: using the opportunity of constructing the Xiongan New Area to build a multi-centered spatial pattern with the government's active guidance and the function of the market mechanism; understanding the importance to form a rational and orderly spatial structure of urban system; breaking the obstacles owing to administrative boundaries among cities to promote the regional integration.

在京津冀协同发展上升为国家战略以及雄安新区战略提出的背景下,检验京津冀城市群大小城市间的经济增长关系,可以为地区协调发展提供学术依据。研究发现：核心城市抑制了周边小城市的经济增长,存在集聚阴影和“环京津贫困带”;小城市之间也存在经济增长负面溢出效应;与长三角城市群相比,京津冀城市群内核心城市辐射和带动功能明显不足,区内城市间的发展差距更大。未来应实现多中心空间发展战略,抓住雄安新区建设的战略契机,在政府积极引导和尊重市场规律的前提下,打破行政分割,促进区域协调分工,形成大中小城市合理有序的城市群空间结构体系。

This article introduces the reaction degree coefficient and the influence coefficient, constructs the industrial contact intensity model, and analyzes the spatial network characteristics of industries in the Changjiang River Delta and Beijing-Tianjin-Hebei (BTH) metropolitan region through the model of industry contact intensity. It focuses on the difference between the two regions and research the formation of metropolis shadow. The results show: 1) the better the industries contacts among the cities in region, the higher the economy level of region; 2) the better the industries between central city and other cities in region, he higher the economy level of region; 3) from the perspective of industries spatial contacts, the weak industry contact between central city and outlying areas is the key reason for the metropolitan shadow’s formation.

通过引入感应度系数和影响力系数,构建产业联系强度测度模型,探讨了当前长江三角洲与京津冀城市群产业空间联系特征,研究了两大城市群空间经济差异,基于产业空间联系视野对“大都市阴影区”的形成进行了实证研究。研究表明：① 城市群内部各城市间产业联系强度越高,城市群整体经济发展水平就越好;② 城市群的中心城市与其他各城市产业联系强度越高,城市群整体经济发展水平就越好、越趋于均衡;③从产业空间联系来看,中心城市与其邻近的外围地区的产业联系强度弱化是造成 “大都市阴影区”形成的关键因素。

We analyse the geographies of urban networks created by leading producer services (PS) firms in China. Because of the national regulation of the Chinese state-led economy and the location strategies of global advanced producer services (APS) firms, the geography of global APS in China as examined by the Globalization and World Cities Research Network (GaWC) cannot be studied as a subnetwork of GaWC’s global network, but needs an empirical study based on a wide range of leading PS in the Chinese market. We explore the spatial differentiation in the connectivity of Chinese cities based on the location strategies of 323 APS firms in 287 Chinese cities. Beijing, Shanghai, Guangzhou and Shenzhen emerge as the primary nodes. The spatial distribution of banking, securities, and insurance services networks appears to be more even than those of non-financial PS firms. Regional disparity exists in terms of polycentric urban development in coastal China, as well as in the centralisation model in central and western areas. We suggest that owing to the continued tight regulation of China’s state-led economy and the nature of the location strategies of ‘globalised’ PS firms, the urban networks created by Chinese PS firms are not only an extension of urban networks at a global scale but also an embodiment of economic activities at other scales.

We examine causes and consequences of relative income within households. We show that the distribution of the share of income earned by the wife exhibits a sharp drop to the right of 12, where the wife’s income exceeds the husband’s income. We argue that this pattern is best explained by gender identity norms, which induce an aversion to a situation where the wife earns more than her husband. We present evidence that this aversion also impacts marriage formation, the wife’s labor force participation, the wife’s income conditional on working, marriage satisfaction, likelihood of divorce, and the division of home production. Within marriage markets, when a randomly chosen woman becomes more likely to earn more than a randomly chosen man, marriage rates decline. In couples where the wife’s potential income is likely to exceed the husband’s, the wife is less likely to be in the labor force and earns less than her potential if she does work. In couples where the wife earns more than the husband, the wife spends more time on household chores; moreover, those couples are less satisfied with their marriage and are more likely to divorce. These patterns hold both cross-sectionally and within couples over time.

Until recently, few people in mainland China would dispute the significance of the hukou (household registration) system in affecting their lives – indeed, in determining their fates. At the macro level, the centrality of this system has led some to argue that the industrialization strategy and the hukou system were the crucial organic parts of the Maoist model: the strategy could not have been implemented without the system. A number of China scholars in the West, notably Christiansen, Chan, Cheng and Seiden, Solinger, and Mallee, have begun in recent years to study this important subject in relation to population mobility and its social and economic ramifications. Unlike population registration systems in many other countries, the Chinese system was designed not merely to provide population statistics and identify personal status, but also directly to regulate population distribution and serve many other important objectives desired by the state. In fact, the hukou system is one of the major tools of social control employed by the state. Its functions go far beyond simply controlling population mobility.

Cities recapitulate a universal pathway into innovative economies.

In the past decade, rapid output growth and employment in the producer services of China have interested the academic sphere in spatial cluster and elaboration of locational theory concerning producer services' activities. The article examines spatial clusters and location characteristics of producer services in the Chinese urban system in the years 2000, 2005 and 2010. This study indicates that the location of cities of a large number of employments of service sectors is dispersed in China, comparing to geographical concentration of cities of developed manufacturing industry. Most of producer services experienced a spatially-centralization process in the period 2000-2010. However, there are different cluster modes in various service sectors. According to characteristics of industry agglomeration, these industries are classified into three modes, namely Primate City cluster mode, Rank-Size distribution mode and Balanced distribution mode. Primate City cluster mode means the largest city of industry have overwhelming employment scales, cluster characteristics of information service industry and business service industry. The number of employment of technology and science service industry as well as real estate in the largest cities is slightly more than other classes of cities. Thus these two industries are classified as Rank-Size distribution mode. Although the number of employment of finance and insurance service has increased in the first class cities, the largest city has no advantage of urban system and the number of employ is relatively balanced in urban system. Therefore, this industry is categorized as Balanced distribution mode. Moreover, the analysis of location quotient and scale of employment evidences there is positive correlation between amount of employment and the number of superiority functions. This means that distribution of producer services in China is in accordance with central place theory. Finally, the study also shows there are complementarities and division of labor among of cities in the same provinces and developed metropolitan regions.

2000年以后,中国生产性服务业高速发展,产业格局逐渐形成。利用2000年、2005年和2010年3个年份地级市行业从业人员的数据,通过区位基尼系数和空间自相关性分析,发现中国生产性服务业在地理空间中整体呈现点状集中的模式,进而对不同行业的集聚特点进行比较分析,认为信息服务业和商务服务业是首位城市集聚模式,科研技术服务业和房地产业是位序规模分布的模式,金融业则是均衡分布的模式。最后,结合主要城市行业的相对优势度分析,得出随着从业人员的增加,承担的生产性服务功能更加综合,符合中心地理论的特点,在省域和城市群内各城市具有较好的职能分工和互补性。