ADDITIVE-INTERACTION MODELS OF SPATIAL AGGLOMERATION*

A wide variety of existing models of spatial agglomeration postulate additive-interaction effects among agents. In this paper, a synthesis of such models is achieved by establishing certain mathematical equivalences between them. In particular, it is shown that Rockafellar's conjugacy theory of concave functions yields a symmetric one-to-one correspondence between three classes of existing models, here designated as spatial-accessibility models, endogenous-contact models, and fixed-contact models. These correspondences not only allow the transference of results between models, but also suggest new economic interpretations of each model in terms of its conjugate model. A series of examples are drawn from the literature to illustrate these results.     

AGGLOMERATION EXTERNALITIES,PRODUCTIVITY, AND TECHNICAL INEFFICIENCY*

ABSTRACT Agglomeration externalities can have positive effects on both the production possibility frontier and technical inefficiency of firms. Increased levels of localized knowledge spillovers and substitution of internal inputs with external inputs may lead to fewer errors in decision‐making and execution of production tasks, thus causing firms to become technically more efficient relative to the production frontier. When we estimate a stochastic frontier production model on a large panel of salmon aquaculture farms, we find econometric support for positive agglomeration externalities on both the production frontier and technical inefficiency.     

DISENTANGLING AGGLOMERATION ECONOMIES: AGENTS,SOURCES, AND SPATIAL DEPENDENCE*

ABSTRACT This paper expands the literature on agglomeration economies in three ways. It disentangles amenity and productivity effects of agglomeration; it decomposes aggregate scale effects into agglomeration factors of interest to policy makers; and it estimates own effects and spillovers to neighbors. It proposes a spatial simultaneous equations model in a spatial equilibrium framework with three agents—workers, consumers, and producers of traded‐goods and housing. Results for Ohio counties estimate economies resulting from population size, agglomeration causes, and public service quality and cost on each of the three agents in own and neighboring counties.     

PRICING POLICY REACTIONS TO AGGLOMERATION IN A MARKET WITH SPATIAL SEARCH*

ABSTRACT. Price dispersion (variation) and agglomeration are common characteristics of spatial markets, in particular, markets with imperfect consumer information and search. However, pricing and location strategies in these markets are not well analyzed since spatial search is difficult to model without restricting the spatial dimension of the problem. This paper analyzes pricing and location strategies in a market with spatid search using a probabilistic modeling strategy that does not restrict search patterns in the plane. Specifically, the analysis considers the pricing strategy of an isolated firm in response to the agglomeration of competing firms. Results indicate that spatial and temporal price dispersion are effective responses to competitors'agglomeration. However, the relative effectiveness of these strategies varies with market conditions. In addition, agglomeration can have some counterintuitive effects. This paper also provides insights into existing theories of spatial search and spatial competition in spatially-restricted (linear and circular) markets.     

德国统一的空间经济格局变化分析

本文介绍了德国统一的背景及统一前的经济景观,论述了统一产生的问题及面临的挑战,进而在分析了人口迁移流与失业率变化的基础上探讨了统一后的空间经济格局的变化趋势。     

PRODUCTIVITY GROWTH IN THE OLD AND NEW EUROPE: THE ROLE OF AGGLOMERATION EXTERNALITIES

As Europe is currently characterized by huge disparities in the economic performance of “old” and “new” states, we investigate whether this is the result of local agglomeration—specialization and diversity—externalities. Our spatial econometric analysis focuses on total factor productivity dynamics over the period 1996–2007 for 13 industries located in 276 European regions. Consistently with the “nursery cities” theory, we find that diversity exerts a positive effect in the knowledge‐intensive services of the “old” Europe urban areas, while specialization is still effective in the “new” Europe low‐tech manufacturing. Human and technological capital has also a positive impact.     

AGGLOMERATION AND REGIONAL COSTS OF LIVING*

ABSTRACT Standard models of the new economic geography predict that costs of living are lower in the core than in the periphery. But in reality they tend to be higher in agglomeration areas, mainly because of regional differences in housing costs. In this paper, we add a home goods sector to the seminal NEG model of Krugman (1991) . We show that a core–periphery structure can endogenously emerge in which the core is the more expensive area. This result has an important normative implication. Since higher costs of living imply falling real wages if there is no nominal wage premium, it is not desirable for everybody to live in the core region.     

AGGLOMERATION,TRADE, AND SPATIAL DEVELOPMENT: BRINGING DYNAMICS BACK IN*

ABSTRACT The field of spatial economics has made enormous progress in theorizing and measuring agglomeration effects, trade costs, and urbanization. Typical models establish structural determinants by making strong assumptions about which forces are relevant and how these forces interact. But many of these assumptions, about firms, agents, spatial costs, and market structures, are questionable. As a result, the field has a long way to go to establish causality, and to be able to account for spatial economic dynamics.     

现代服务业集聚形成机理空间计量分析

在纳入空间效应前提下,构建现代服务业集聚形成机理空间面板计量模型,对我国28个省域相关数据实证研究表明:我国现代服务业集聚在省域之间有较强的空间依赖性和正的空间溢出效应。技术差异在时间维度上对现代服务业集聚促进作用显著,在空间维度上并不显著;交易费用与现代服务业集聚有显著的负相关性;知识溢出、规模经济、政府行为对现代服务业集聚促进作用显著。     

北部湾城镇群空间结构及其扩张规律研究

空间结构是优化城镇群地域功能的基础。根据新型城镇化和空间结构理论,用地统计、反距离权重等空间分析方法,研究广西北部湾城镇群空间结构分异规律得出：(1)北部湾城镇群以南宁市为中心向周边呈“核心—边缘”分异格局,时空集聚性和差异性渐趋扩大。(2)大城市空间聚集和结构分异不断增大,社会、经济要素空间扩张显著快于人口、土地要素,对外贸易和吸引投资是空间扩张的核心动力,非农化增长也是重要驱动。(3)城区面积与空间结构关系最密切,但投资、贸易、GDP、非农化扩张较快,人口、土地要素空间扩张显著滞后,各要素向大城市集聚的趋势显著,结构分异趋向扩大;绝大部分属于外贸、投资扩张型城镇。应强化南宁市集聚规模,提升工业化水平,扩大区内外合作,全面融入“一带一路”和大湾区新格局。     

THE MAGNITUDE AND CAUSES OF AGGLOMERATION ECONOMIES*

ABSTRACT Firms and workers are much more productive in large and dense urban environments. There is substantial evidence of such agglomeration economies based on three approaches. First, on a clustering of production beyond what can be explained by chance or comparative advantage. Second, on spatial patterns in wages and rents. Third, on systematic variations in productivity with the urban environment. However, more needs to be learned about the causes of agglomeration economies. We have good models of agglomeration through sharing and matching, but not a deep enough understanding of learning in cities. Despite recent progress, more work is needed to distinguish empirically between alternative causes.     

REGIONAL WAGE DIFFERENCES IN THE NETHERLANDS: MICRO EVIDENCE ON AGGLOMERATION EXTERNALITIES

Based on micro data on individual workers for the period 2000–2005, we show that wage differentials in the Netherlands are small but present. A large part of these differentials can be attributed to individual characteristics. Remaining effects are partially explained by variations in employment density, with an elasticity of about 4.8 percent, and by Marshall‐Arrow‐Romer externalities, where doubling the local share of a (two‐digit) industry results in a 2.9 percent higher productivity. We also find evidence for small negative effects of competition (Porter externalities) and diversity (Jacobs externalities).     

LOCAL ECONOMIC IMPACTS OF NATURAL DISASTERS*

ABSTRACT This research uses time‐series analysis under a quasi‐experimental pair‐wise matching design to examine local economic impacts of the 1993 Midwest flood. The data support the concept of overall local economic resiliency to natural disasters. The flood's impacts on total employment were minimal. Although significant drops in personal income were observed in the year of the event, the long‐run effects seemed to be negligible. This study also finds that the flood's negative impacts on agriculture were significant and long lasting to some Midwestern communities. The findings are quite stable with respect to the number of controls selected for each treated unit.     

基于空间分析方法的武汉市创意产业空间集聚演化研究

通过ArcGIS利用区位商、最近邻距离分析、核密度分析与定向分布分析等多种方法综合分析武汉市创意产业空间集聚的演变特征。结果表明,武汉市创意产业总体呈集聚状态,依据发展水平差异可分为核心区、潜力区与待发展区,并主要集聚在汉口"核心圈"与武昌"潜力轴"上。城市内创意产业功能分布与集聚分布主要呈由内向外扩展的演变特征。但根据产业特征、发展基础与发展阶段的不同,不同创意产业部门在不同区域的集聚形态、集聚强度、空间演化过程及发展趋势存在差异。这些差异与创意人才机构、文化传播设施以及创意交流空间集聚存在密切联系。     

上海大都市区物联网产业集聚与空间演化

新兴技术产业的空间集聚与扩散对大都市区的空间结构有直接的影响,厘清新兴技术产业的空间分布和区位选择规律对新兴产业集群培育和大都市区空间结构调整都具有重要的政策意义。本文分析了上海市物联网企业的空间分布和集聚特征,结果发现初创期物联网企业在郊区集聚,随后向郊区其他区域扩散,并呈现出从单极向多极集聚转变的空间演化进程。通过构建负二项回归探究上海物联网企业的区位选择因素,结果表明制度因素和企业集聚效应对企业区位选择有重要影响。在产业发展初创期,企业区位选择受政府管制和市场机制双重影响,其中制度因素发挥了关键作用;而在随后的兴起期,产业集聚效应对新企业的入驻具有强大的吸引力。     

广东省创意阶层集聚的时空演变及其影响因素分析

以广东省21个地级市为例,利用ESDA分析方法和2000-2012年的数据,对广东省创意阶层的空间集聚特征和演变趋势、影响因素进行了初步探索。结果表明:广东省创意阶层的空间分布存在明显差异,主要集中在珠三角地区,东西两翼和粤北山区分布较少,与广东省经济格局较为一致,集聚呈现二元结构;在总体空间格局上,区域创意阶层分布存在显著的空间正相关特征,空间整体差异呈现先缩小后扩大的趋势;各地级市自身与周边地区的相互联系比较微弱,创意阶层高聚集区的辐射和带动作用不明显。从创意阶层空间集聚的影响因素看,不同时间段的显著影响因素存在差异。总体上,科技是持续显著影响广东省创意阶层空间集聚的因素,其次是社会人文因素和城市的工资水平。     

THE FUTURE OF SPATIAL ECONOMETRICS*

ABSTRACT The purpose of this paper is threefold. First, we give an overview of the general direction the spatial econometrics literature has taken without attempting to provide a representative survey of all interesting work that has appeared. Second, we identify a number of problems in spatial econometrics that are as yet unresolved. Finally, we provide advocacy for the notion that new spatial econometric theory should be inspired by actual empirical applications as opposed to being directed by what appears to be the most obvious extension of what is currently available.