集聚与中国城市经济韧性

近年来中国经济增速有所下降,但各个城市在经济下行压力下的表现并不相同,本文从人口集聚的视角研究城市经济韧性。首先利用空间均衡模型分析集聚如何影响生产率进而作用于城市经济韧性,在此基础上建立长差分模型识别集聚和城市韧性的关系。研究发现:集聚不但有助于提高城市抗冲击的能力,也能够提升城市经济恢复的能力以及冲击后状态转变的能力;与经济下行时期相比,经济调整时期集聚与城市韧性的关系更为密切;市场需求效应、高技能劳动力的流入及知识溢出是集聚影响城市韧性的主要途径;集聚效应存在空间异质性,集聚对全国总体经济韧性有明显影响。本文研究表明,促进人口集聚是应对经济下行压力、增强城市韧性的有效举措。     

产业协同集聚对绿色全要素生产率的空间效应研究——来自京津冀城市群的经验证据

绿色发展是推进京津冀城市群经济高质量发展的关键之举。文章基于2006—2019年京津冀城市面板数据，采用空间计量方法实证分析制造业与生产性服务业协同集聚对绿色全要素生产率的直接影响及空间溢出效应。研究发现：在正、负外部效应双重作用下，产业协同集聚对京津冀城市群绿色全要素生产率具有“倒U”型影响，同时存在空间溢出效应；进一步分析发现，该影响效应存在产业异质性，制造业与高端生产性服务业协同集聚对绿色全要素生产率具有更强的作用效果以及更高的拐点值，且产业协同集聚能够通过绿色技术效率及绿色技术进步“双引擎”作用于绿色全要素生产率。研究结果可为如何依托产业协同集聚促进京津冀城市群绿色发展提供一定的参考。     

外资集聚、技术创新与地区经济增长--基于省级面板数据的空间计量分析

文章选取我国30个省市1995-2011年的数据,应用空间计量方法对外商直接投资、技术创新的空间效应及其对地区经济增长的影响进行了实证检验。结果发现：我国外商直接投资和技术创新具有明显的空间集聚效应和循环累积效应,外资和技术创新的空间集聚效应对地区经济增长具有积极的促进作用;外商直接投资和技术创新在我国地区之间并不存在互补性,而是表现为竞争关系,外资和技术创新的空间集聚在一定程度上引起了地区收入差距的扩大;我国外商直接投资、技术创新和地区收入之间的相互影响关系仍然受地理距离的影响,临近区域的空间溢出和关联效应比较明显,可以部分解释我国不同经济区域之间发展差距的形成和扩大。     

旅游产业集聚对经济增长的空间溢出效应——来自长三角地区的经验研究CSSCI

本文以持续推进旅游一体化的长三角地区30个城市为研究对象,探讨了旅游产业集聚对经济增长的空间溢出效应及影响因素。基于这些城市2005-2014年的空间面板数据,本文采用空间杜宾模型,对比空间相邻矩阵、地理距离加权以及经济距离加权的空间权重矩阵的实证结果,发现城市间的经济增长的确存在空间上的正外溢,而且这一效应会随着地理距离和经济距离的缩小而明显增加。但是,旅游产业集聚密度和集聚规模对经济增长的影响却存在着显著差异。前者不仅能促进本地经济增长,而且存在正的空间外溢效应;后者不仅抑制了本地经济增长,而且存在负的空间外溢效应。进一步实证研究发现,相邻城市之间地理距离的缩小促进了集聚密度正效应的外溢和集聚规模负效应的外溢,经济距离的缩小即旅游规模的相似,在促进集聚密度正效应外溢的同时抑制了集聚规模负效应的外溢。     

数字经济、流动空间与城乡收入差距

在城乡融合发展和“数字中国”战略背景下,明晰数字经济发展对城乡收入差距的影响逐渐成为推进中国式现代化的焦点问题。基于2011-2019年中国217个地级及以上城市数据,探究数字经济对城乡收入差距的作用机制及其空间溢出效应。结果表明：数字经济发展缩小了城乡收入差距,并大致呈现出“L型”的非线性作用关系;数字经济能通过提升市场活跃度和促进农村电商集群间接缩小城乡收入差距;由于经济发展与要素集聚水平的差异,东部地区、中心城市的数字经济缩小城乡收入差距作用相对较强。同时,数字经济对城乡收入差距的收敛效应具有“本地-邻地”的空间溢出效应;进一步分析证实,不同空间半径权重下,数字经济可通过网络技术优势,增强经济活动与组织交换的“流动空间”势能,弱化空间作用“边界”,促使“邻地”收敛效应突破地理距离约束。     

数字经济、流动空间与城乡收入差距北大核心

在城乡融合发展和“数字中国”战略背景下,明晰数字经济发展对城乡收入差距的影响逐渐成为推进中国式现代化的焦点问题。基于2011-2019年中国217个地级及以上城市数据,探究数字经济对城乡收入差距的作用机制及其空间溢出效应。结果表明:数字经济发展缩小了城乡收入差距,并大致呈现出“L型”的非线性作用关系;数字经济能通过提升市场活跃度和促进农村电商集群间接缩小城乡收入差距;由于经济发展与要素集聚水平的差异,东部地区、中心城市的数字经济缩小城乡收入差距作用相对较强。同时,数字经济对城乡收入差距的收敛效应具有“本地-邻地”的空间溢出效应;进一步分析证实,不同空间半径权重下,数字经济可通过网络技术优势,增强经济活动与组织交换的“流动空间”势能,弱化空间作用“边界”,促使“邻地”收敛效应突破地理距离约束。     

中心城市综合承载力对经济增长的空间溢出效应

高质量发展需要提高中心城市综合承载及资源优化配置能力,中心城市综合承载力提升对区域经济增长将产生重大影响。传统的经济增长模型无法考量其空间相关性,因此需要深入探析中心城市综合承载力对区域经济增长的空间效应。文章构建双向固定效应空间杜宾模型检验中心城市综合承载力对区域经济增长的空间溢出效应。研究表明：中心城市综合承载力具有空间外溢性与空间关联性,不论是中心城市综合承载力对经济增长,还是资本与劳动产出对经济增长均有空间溢出效应。同时,中心城市综合承载力作为资本与劳动集聚的空间载体,其通过资本与劳动的聚集作用与空间溢出效应对经济增长产生重要影响。此外,分空间区域检验中心城市的空间溢出效应。京津冀地区对其经济增长有较强的虹吸效应,长三角与珠三角地区对其经济增长有较强的辐射及空间扩散效应。     

产业集聚、FDI与城市创新能力——基于我国264个地级市数据的空间杜宾模型

本土产业集聚模式会显著影响FDI在城市创新中的溢出效应,但是鲜有文献在研究FDI对城市创新能力影响时考虑了本土产业结构与FDI是否相互匹配的问题。文章在新经济地理学的框架下,首先分析了本土产业集聚模式影响FDI溢出效应的作用机制,并基于我国2008-2013年264个地级及以上城市的面板数据,利用空间杜宾模型实证研究了本土产业集聚模式如何影响FDI在城市创新中带来的区域内与区域间溢出效应。结果表明:产业集聚与FDI都能够产生明显的外部性,产业集聚对FDI溢出效应的影响受到地区差异、城市规模差异的约束。从整体上来看,相比于多样化集聚,本土产业专业化集聚更容易吸收和传播FDI的溢出效应,提升城市创新能力的作用更明显。从分区域层面来看,东部地区产业多样化集聚提升FDI的溢出效应作用显著,而中西部地区FDI的溢出效应更多的受益于专业化集聚。从分城市规模来看,特大规模城市应该选择多样化集聚模式,而大中小三种规模城市则应该更多地专注于专业化集聚模式。     

高新技术产业集聚、科技创新与经济增长

文章基于2002—2019年中国30个省份的面板数据，首先采用改进的区位熵测度各省份高新技术产业集聚水平，然后采用熵值法对各省域科技创新进行评价。通过全局Moran′s I指数检验区域经济增长的空间溢出效应，在此基础上建立空间计量模型检验科技创新在高新技术产业集聚与区域经济增长之间的中介效应。实证发现：各省份高新技术产业集聚与科技创新的分布情况具有很强的相似性；在3种不同的空间权重矩阵下，全局Moran′s I指数均显著为正，说明区域经济增长存在明显的正向空间溢出效应；通过中介效应检验得出，科技创新在高新技术产业集聚与区域经济增长之间起中间传导作用。     

技术溢出、环境污染与经济增长

大多数新经济地理模型主要关注产业空间分布的长期均衡问题,而忽视了对该地区经济增长的关注。本文将内生经济增长理论融入新经济地理模型,并在考虑到技术溢出与环境污染对企业固定生产成本的影响情况下,探讨了技术溢出效应和环境污染效应对产业空间演化和经济长期增长的影响。研究发现：本地技术溢出效应的增强和跨界技术溢出效应的减弱是促使企业走向集聚的动力,本地环境污染效应的增强和跨界环境污染效应的减弱是促使企业走向分散的动因。产业空间结构的稳态并非都必然表现为棒棒均衡结构的特征,贸易自由度的变化可以引起任何形式的产业空间结构稳态。当技术溢出向心力不低于环境污染离心力时,随着贸易自由度的增加,产业空间演变的总趋势为“分散-集聚”;反之,产业空间演变的总趋势为“分散-集聚-再分散”。     

On the Major Transformation of the Asia-Pacific Regional Structure北大核心CSSCISSCI

Recent years have witnessedsignificant changes in the Asia-Pacific regionalstructure featuring the shift in power balance among related countries as well as adjust-ments in their respective regional strategies. So what is the prevailing trend in thistransformation and what kind of regional order will likely emerge in the future？ To an-swer these questions, the paper tries to explore the following dimensions： the evolvingregional context, shift in power balance and power conversion, geo-political and geo-e-conomic developments and interactions between them, and evolving regional order. Asthe study shows, the broadening of regional geographical scope, the rise in the numberof actors involved, as well as changesin the relations among them, have combined tocast a pluralistic and complex flavor to the regional structure. While the power balanceamong China, the United States and Japan shifts, and power conversion is also occur-ring. China and Japan are paying increasing attention to their security roles, whereasthe United States under the Obama administration laid more stress on expanding itsgeo-economic clout. In spite of the intensifying geopolitical competition among China,the United States and Japan in recent years, a Sino-US strategic compromise-whichholds the key to regional geopolitics-isother front, some kind of geo-economicmore likely to take place in the future. On thecooperation will probably emerge. In the longerterm, it will be the geo-economic trend thatwill prevail over the geopolitical trend inthe region. Finally, the future evolution of regional order wiI1 mainly follow the eco-nomic logic, accompanied by the dilutionof its hegemonic and hierarchical nature.Hence, a pluralistic and complex regional community will emerge.     

The German Hanse and Bergen – new perspectives on an old subject

Abstract

The Hanseatic League and her kontors (trading posts) were an integral part of the medieval trade system in Northern Europe. Hanse merchants dominated many markets in this region and managed to maintain a monopoly-like role in towns like Novgorod and Bergen for many centuries. Consequently, one focus of historical research about the Hanseatic League lay on the mechanisms that enabled the Hanse merchants to keep that strong of a position for such a long time.

This article is part of the discussion about this topic. Based on Lübeck merchants with business interest in the Norwegian town of Bergen, the so-called Bergenfahrers (Bergen travellers), it will give new insights into the Hansards' economical and social organization. The three main points are (a) the integration of the Bergen market in the Hanseatic trade network as an intermediary trading place on the vivid East–West route of Hanse trade; (b) the importance of the Bergenfahrers within the Hanse merchants' economical, social and political networks; and (c) the structure of the Bergenfahrers network patterns in the late Middle Ages.

In addition to new insights into the important role of Bergen and the Bergenfahrers within Lübeck's and the other Wendish Hanse towns' trading system, this articles provides further proof for the usefulness of the methods of Social Network Analysis in medieval economic research.     

Organization and incentives in the age of sail

The British Navy in the age of sail was the most successful bureaucracy of its time. Its organization and incentive structures differed importantly from contemporaneous private sailing ventures, but closely resembled those of today’s large corporations. To induce efficient effort, the navy used a hierarchical tournament, in which sailors competed for higher pay that came with promotions based on relative performance. Promotion probabilities, the option value of future promotions, and the higher effort required of men in higher ranks and on larger vessels, combined to yield a highly skewed pay structure.     

Financial Reporting and Trade Credit: Evidence from Mandatory IFRS Adoption*

We investigate the effect of mandatory IFRS adoption on trade credit. We document that firms in countries that adopt IFRS receive more trade credit from their suppliers, consistent with improved financial reporting quality and comparability playing a role in facilitating informal financing. This increase is larger for countries with a low level of societal trust, a poor pre‐IFRS‐adoption information environment, and stronger legal enforcement. These cross‐sectional results suggest that the conditions under which higher‐quality information is made publicly available affect suppliers' decisions to provide trade credit. This increase is also larger for firms with greater exposure to foreign markets, a finding that highlights the importance of more comparable international financial reporting standards in facilitating cross‐country trade credit. We also find that IFRS adoption has a stronger positive effect on trade credit for firms with greater liquidity needs. Finally, we find that firms in countries that adopt IFRS also extend more trade credit to their customers. Overall, our results support the notion that financial reporting can have a causal effect on trade credit.     

区域工业产业竞争力指标体系的构建及其评价方法研究

文章通过建立省级区域工业产业竞争力评价指标体系,设计竞争力模型,利用SPSS统计软件,对各省工业产业竞争力进行了评价测定。     

中俄经济技术合作面临新机遇

中俄在十年内把各自的GDP翻一番的目标,为发展中俄经济技术合作提供了机遇.仅仅依靠商品贸易的增长很难大幅度提升中俄经贸关系,需要全面开展经济技术合作,特别是加强在自然资源开发、跨国投资、军工技术和产品贸易领域的合作.     

Penetration and Post-infection Development of Meloidogyne Incognita on Tobacco as Treated by Rhizobacteria Pseudomonas Fluorescens Strain P-72-10

The bio-control potential of rhizospere bacteria Pseudomonas fluorescens against plant-parasite nematode had been demonstrated. P. fluorescens had shown the effect to enhance tobacco resistance to root-knot nematode Meloidogyne incognita. Inoculation with P. fluoreseens in tobacco could lead to significant reductions in the number of juveniles that penetrated tobacco root and further life stage development of the juveniles. The number of juveniles penetrated into tobac- co root in treatment with P. fluorescens is significantly different from CK at 2DAI, 6DAI, 8DAI and 10DAI. Significant reduction and delayed development of juveniles that penetrated into tobacco root and treated were observed in treatment at 14DAI, 21DAI, 28DAI and 35DAI. In addition, P. fluoreseens treatment leads to a significant reduction in the number of eggs per egg-mass at 35 DAI. The results show P. fluorescens induced a continuously suppression on root-knot nema- tode M. incognita throughout their entire early infection phase of root penetration, subsequent life stage development and reproduction.