The High-Volume Return Premium

The idea that extreme trading activity contains information about the future evolution of stock prices is investigated. We find that stocks experiencing unusually high (low) trading volume over a day or a week tend to appreciate (depreciate) over the course of the following month. We argue that this high-volume return premium is consistent with the idea that shocks in the trading activity of a stock affect its visibility, and in turn the subsequent demand and price for that stock. Return autocorrelations, firm announcements, market risk, and liquidity do not seem to explain our results.     

电子商务对产业竞争结构的影响

哈佛大学著名教授迈克尔·波特提出的竞争战略的相关理论曾经引起了世界范围的大讨论,他提出的用于分析产业竞争结构的五种作用力模型也成为众多企业制定竞争战略的基本分析方法。电子商务的发展已使传统的产业结构发生了重要变化,本文正是以波特教授的五力模型为基础,从进入威胁、现有竞争对手的竞争、替代威胁、买方侃价能力和供方侃价能力五方面分析了电子商务环境下产业结构的变迁。     

网络外部性与软件产业技术扩散

对我国软件产业而言,缺乏核心技术是制约发展的瓶颈问题,而技术扩散是解决软件产业技术落后的主要方法。本文从网络外部性的角度入手,分析了软件产业网络外部性的特点、网络外部性对软件产业的影响、以及在网络外部性下形成的不同市场结构,并以“结构一行为一绩效”的产业组织分析范式为基础,研究了不同市场结构下软件产业的技术扩散行为。     

An empirical analysis of strategy types

Using the PIMS SPIYR data base, which pools cross-section and timeseries data, an empirical study to identify business strategy types was undertaken. Using a two-stage methodological approach combining principal component and cluster analysis on both a consumer products and an industrial products data base, two sets of strategy typologies were identified. Six strategy types were identified for consumer products: (1) harvest, (2) builder, (3) cashout, (4) niche or specialization, (5) climber, and (6) continuity. For industrial products, four strategy types were identified: (1) low commitment, (2) growth, (3) maintenance, and (4) niche or specialization. A discussion of the characteristics of each strategy type is offered.     

中国的经济结构、增长速度与能源效率

从我国能源利用效率变动的历史轨迹可以发现,2000-2005年我国单位GDP能源消耗呈上升趋势.能耗上升的主要原因:从经济结构的角度来看,主要是高耗能产业发展加速,能源消费向高耗能行业集中;国际产业分工低端化,工业增加值率下降;在能源进口不断增长的同时,高载能产品出口大幅度增长.从经济增长的角度来看,速度过快,超过我国经济增长潜力,导致能源过度投入.为提高我国能源利用效率,应采取必要的政策和法律措施:把提高能源与资源利用效率、减少污染作为经济结构调整的重要标准;运用宏观调控手段,保持经济的适度增长;完善能源价格体系,充分发挥价格税收的调节作用;把提高能源利用效率作为自主创新和技术进步的重要目标;运用法律与行政手段,加强能源生产与消费的外部性监管.     

并网式环保LED广告牌设计与分析

综合并网发电控制技术和LED的并网式环保LED广告牌,运用铅酸蓄电池,以太阳能为主、市电为辅的供、放电控制系统,通过光控和计时管理控制技术,能实现白天充电,晚上放电,智能控制整个工作过程。该系统利用了太阳能和LED节能环保的特点,具有较强的推广价值。     

基于有效集检验CAPM对中国股票市场的有效性

资本资产定价模型(CAPM)有效性的主要假设是市场组合位于全局均值-方差有效集上,有效集理论可用来对CAPM的有效性进行检验.本文利用沪深股市1991～2008年的数据对CAPM在中国股票市场的有效性进行了检验,综合检验的结果表明:中国股票市场趋于有效.     

Analysis of China＇s Renewable Energy Development under the Current Economic and Technical Circumstances

At present, the development of renewable energy relies mainly on government support. The government invests in a considerable number of projects to improve public welfare and to assist in poverty relief If China is to replace fossil fuels on a large scale with renewable energy sources, the production costs and prices of renewable energy must be brought down. All countries are facing the challenge of moving to a more secure and low-carbon energy system without weakening economic and social development. In this regard, China is facing an even greater challenge in terms of economic cost, as cheap coal remains the main energy form. Technical innovation and industrialization in the area of renewable energy is an important means of lowering cost. China is in for a period of high-speed development of its economy and the rising demand for energy is irreversible. If the technical progress and development speed of renewable energy lags behind the growth in demand, it will be difficult to realize the improvement of its energy structure.     

郊区到城市的转变——以长沙市都市区内小城镇的发展为例

通过对长沙市都市区内小城镇发展状况的剖析,指出在长株潭城市群成为全国资源节约型和环境友好型社会建设综合配套改革试验区的背景条件下,长沙都市区内的小城镇面临良好的发展机遇,同时也面临一系列的问题,并从规划层面提出建议,以期促进其由郊区向城市的成功转变。