中国发展知识经济的空间结构

发展知识经济可以有效解决中国所面临的诸多挑战。文章探讨了经济发展的空间结构理论、城市与现代经济的关系、中国发展知识经济的路径选择,提出中国发展知识经济的空间结构是“升岛成陆”,即以各级有条件的城市特别是大城市为主先行发展知识经济,然后带动其它地区,扩大发展知识经济的区域,从而最终像地球科学中的升岛成陆造地运动一样,实现全国发展知识经济。同时,要通过行政区划制度创新促进这一进程,要将一些大城市升格为直辖市。     

Racing in two dimensions

In this paper we study an industry in which there is an ongoing sequence of R&D races between two firms. Firms are engaged in product innovation. Products are horizontally and vertically differentiated. There are two key characteristics/dimensions to products, and the level at which these are embodied in products can be increased by R&D. At each time firms can spend R&D on improving their product in one or both dimensions. We allow the possibility of economies scope — so R&D undertaken in one dimension can spillover to the other. The question we are interested in is whether a firm that is ahead in a single dimension but behind in another will focus all its R&D effort in the area in which it is ahead (product specialisation), or whether it will try to do R&D in both dimensions in the hope that it might get ahead in both and end up with a superproduct that dominates in both characteristics. The outcome of this R&D competition determines a Markov transition probability matrix determining the evolution of the industry. We show that when the R&D technology is characterized by constant returns then the only steady-state outcome is one in which the economy stays forever in a position in which one firm produces a super-product and the other gives up doing R&D altogether. This outcome is unaffected by the degree of economies of scope. When the R&D technology is characterised by decreasing returns, then the industry will visit all states and so will exhibit both product specialisation and superproduct dominance at various times. Now the extent of economies of scope matters and we show that the greater the extent of economies of scope, the less likely is the industry to exhibit product dominance, and the more likely it is to exhibit product specialisation.     

Mixed Equilibrium in a Downsian Model with a Favored Candidate

This paper examines competition in the standard one-dimensional Downsian model of two-candidate elections, but where one candidate (A) enjoys an advantage over the other candidate (D). Voters' preferences are Euclidean, but any voter will vote for candidate A over candidate D unless D is closer to her ideal point by some fixed distance δ. The location of the median voter's ideal point is uncertain, and its distribution is commonly known by both candidates. The candidates simultaneously choose locations to maximize the probability of victory. Pure strategy equilibria often fail to exist in this model, except under special conditions about δ and the distribution of the median ideal point. We solve for the essentially unique symmetric mixed equilibrium with no-gaps, show that candidate A adopts more moderate policies than candidate D, and obtain some comparative statics results about the probability of victory and the expected distance between the two candidates' policies. We find that both players' equilibrium strategies converge to the expected median voter as A's advantage shrinks to 0. Journal of Economic Literature Classification Numbers: C72, D72.     

信息网络对企业空间组织的影响

信息网络是信息社会的主要基础设施,本文从信息网络的概念、分类和形状入手,讨论了信息网络对企业区位和劳动空间分工的影响,并举例加以说明,最后对地理学开展新的空间经济发展研究提出了思路.     

出生缺陷地理风险因子的空间分析

出生缺陷是影响人口出生质量最重要的因素。大量研究表明,出生缺陷仅仅靠单纯的生物医学研究还不够,多学科的交叉研究是有效探讨出生缺陷病因和预防的唯一出路。利用北京大学人口环境健康组调查数据,分类了能够在地理空间上归属的出生缺陷风险因素,将这些因素存在的空间相关性进行了传统统计分析方法不适宜的风险因子与出生缺陷统计因果之间的研究。探讨了空间分析技术在出生缺陷的地理风险因子研究的一般步骤与关键技术,为出生缺陷研究提供了新的思路。     

知识经济与城市产业空间布局的调整

随着网络等高新技术的飞速发展，世界经济正在从工业经济向知识经济转变，阻碍生产素流动的控制壁垒和自然壁垒明显减少，产业空间区位选择的灵活性大在增强，产业布局将出现分散与聚集共存的趋势，那些以创新为基础的知识密集型产业将形成有规律的集群，大城市中心区也将日益成为跨国公司总部以及银行，保险，管理咨询等生产才高度集中的地区，成为协调全国仍至全球生产的信息和服务中心，根据产业空间演变化的新趋势和我国城市产业布局的现状，作者提出了我国城市产业空间布局的方向和思路。     

休闲城市空间开发模式构建研究

认为空间开发模式的构建是休闲城市建设的一个重要方面;结合旅游为主导的休闲产业发展态势,从区域旅游开发视角对休闲城市空间开发模式进行了探讨.     

RECENT DEVELOPMENTS IN THE THEORY OF NATURAL MONOPOLY

Abstract. This paper examines two important recent developments in the theory of natural monopoly, or more generally the theory of market structure. The first is a series of papers, involving Baumol with various co-authors, investigating the theory of industry structure, whilst the second is particularly associated with the names of Shaked and Sutton, and the relationship they develop between product differentiation and industry structure. The paper surveys and to some extent contrasts these two new approaches.
Baumol et al. 's contribution is seen to be in the area of clarifying the concept of natural monopoly, refining the definitions of multiproduct costs, and developing a notion of social efficiency applicable to industries where economies of scale are important. Shaked and Sutton employ a new definition of natural monopoly unrelated to market size and utilize information about consumers'income distributions to develop their notion of vertical product differentiation and natural oligopoly.     

我国大城市区域空间规划与建设的思考

在当前全球经济一体化与城市化高速发展的新时代,由于城市的空间区域不断扩大、城镇连绵迭加、资源要素的集聚、产业集群转型与重组及其交通信息网络化等等因素的汇合与相互依存,给我国许多大城市地区带来新的问题与新的现象。如何规划与建设这些大城市的区域空间是21世纪"城市时代"越来越突出的大问题。文章就我国大城市区域的空间规划与建设形势、有关理论与创新理念及其策略性问题,进行深入的有益的探索,期望相关的学术争论。     

上海市区商业等级空间的结构与演变

以上海为例,选取上海各个等级商业中心作为研究对象,探讨其发展演变特征和机制,预测未来商业的空间发展趋势,针对当前商业发展中出现的问题提出建议.研究认为,改革开放以后,由于经济水平提高导致的居民购买力下移、城市和交通的发展、消费行为方式的变化等要素的影响,使上海商业中心业态类型多样化,商品种类丰富,综合功能提高,并出现了以空间上的郊区化、等级上的社区化、结构上的扁平化为特征的新的发展趋势.对如何加强社区商业发展、市级商业中心建设、大卖场的合理规划等问题进行了讨论,并提出设想和发展思路.