Market microstructure in a global B2B network

On‐line marketplaces raise several interesting issues, among them the relevance of location when content is digitized, and the assessment of a supplier's capabilities when buyers worldwide only have electronic contact with sellers. In global B2B on‐line marketplaces, market microstructures, i.e. which firms compete for the same customers, are thus likely to be influenced by how customers value location and firm capabilities in their decisions to do business with different suppliers on‐line. We suggest that both these sets of attributes will continue to matter on‐line—firms possessing similar capabilities, as well as firms that are similar in location by country, time zones or clusters, will compete for business from the same customers. We model the similarity in competitive positions between pairs of firms based on the overlap in their customer networks, using data on actual interactions between supplier and customer banks on an electronic trading system. Using QAP network regression techniques on the 100 largest banks in this industry, we find that similarity in capabilities influences who competes with whom, and that location still matters in a global B2B exchange. Interestingly, location influences who a firm's competitors are, but not where its customers are from. Copyright © 2001 John Wiley & Sons, Ltd.     

服务业集聚与产业结构优化关系探究

随着全球化进程的不断加快，服务业集聚已经成为人们普遍关注的话题。产业集聚在获得规模效应的同时避免了垄断现象的产生，服务业集聚不但拥有这样的优势，而且还有自己独特的形成和发展特点。从产业结构的优化角度切入，借助区位商和专门化率等分析指标，以江苏省和上海市为例，对服务业集聚的形成进行理论和实证分析，提出产业结构的优化对于服务业集聚的形成和发展有着积极的作用。合理的产业结构能够为服务业集聚提供坚实的基础，各地区应该根据各自的产业特点积极的进行优化，催生服务业集聚，加快本地区经济的进一步发展。     

Capital market trading volume: an overview and some preliminary conclusions

This paper suggests an explanation for the heavy trading volumeobserved on the US capital markets, the world's largest. Heterodoxeconomic theory puts much of this volume down to speculation.Mainstream theory tends to support this thesis, either directlyor indirectly, by giving space to the idea that trading activityis for the most part exogenous to the functioning of the capitalmarkets. The central hypothesis of this paper is that the tradingvolumes observed are an endogenous feature of the capital markets,because they are to a great extent determined by the needs ofthe institutional investors who predominate on these markets.This endogeneity of trading is posited in connection with theemergence of a new ‘core–satellite’ paradigmin institutional investment, a development that essentiallymanifests the asset-management industry's transformation froma small industry serving a few wealthy clients to a mass industryserving large sections of the population.     

Asymptotic expansion of S-estimators of location and covariance

By means of a straightforward application of empirical process theory, we show that S-estimators of multivariate location and covariance are asymptotically equivalent to a sum of independent vector and matrix valued random elements respectively. This provides an alternative proof of asymptotic normality of S-estimators and clearly explains the limiting covariance structure. It also leads to a relatively simple proof of asymptotic normality of the length of the shortest α-fraction.     

物流配送系统中的运筹学问题及方法研究

物流配送系统中包含诸多运筹学问题,如配送中心选址中的0-1规划问题,货物配载中的背包问题,配送路线优化中的动态规划问题等,通过建立数学模型,利用运筹学方法与信息技术的结合可对上述问题加以解决,为配送业务的进一步发展提供帮助.     

模型算法在企业的场址选择及其内部设施的平面布置中的应用

企业的场址选择及其内部设施的平面布置形式，对于企业的运输费用具有举足轻重的作用。本文对企业和内部设施的布置进行模型设计，并通过层次分析法对场址选择方案进行比选．采用对目标函数的优化对企业内部设施的平面布置形式进行优化。     

江西大型企业资本运作模式的现状及其改进对策研究

资本运作是一种有效配置资源、实现企业资本增殖的活动,其核心是产权制度创新。本文对江西大型企业资本运作模式的现状进行了分析,进而提出了一系列的合理的改进对策,以期提高起运作绩效。     

共同分析师网络与企业异地投资

基于社会网络视角,以2010—2020年中国A股非金融类上市公司为样本,探讨共同分析师网络对于企业异地投资的影响机理及其经济后果。研究发现：共同分析师网络依靠网络中的社会资本及信息传递效应促进企业异地投资,并且这种促进作用在民营企业和第三产业企业中表现得更为明显;经济后果表明,共同分析师网络作用下的异地投资会促进企业创新并提升企业价值,有利于企业健康发展。     

一种适用于高铁沿线的多台站快速地震预警方法

对于地震预警技术来说,根据参与监测预警的台站数量不同,可以将高速铁路地震监测预警系统分为单台站地震P波预警技术和多台站地震P波预警技术。单台站P波预警由于信息量较少以及噪声影响,在定位方面存在较大误差。多台站P波预警技术是在单台站P波预警的基础之上,综合多个单台站信息进行综合震源参数估算并发出地震预警信息的预警方式。通过应用多台站P波预警定位技术,能够在震源估算方面得到更准确的结果。     

Policy options for afforestation in Flanders

This paper analyses current and alternative afforestation policy instruments in Flanders. First we select forest sites that maximize net social benefits given a constraint on the total area of new forests and then we select policy instruments that yield this optimal combination of sites. For each policy option, we calculate the associated costs for landowners and government as well as net social benefits for society. Our empirical illustration shows that the welfare gain is considerable if the afforestation subsidy is conditioned on an objective criterion rather than a case-by-case approach. Our results also show that it is worthwhile to consider alternative policy instruments, such as auctions, not previously used in Belgian legislation.