股价信息含量与投资-股价敏感性——基于融资融券的准自然实验

本文利用2006-2015年间的数据研究了融资融券对投资-股价敏感性的影响。利用融资融券作为股价信息含量的一个外生冲击变量,本文研究发现,我国A股市场确实存在反馈效应,融资融券政策的实施增强了标的公司投资-股价敏感性,这个结论在采用倾向得分模型(PSM)配对后依然成立,说明融资融券使股价融入了更多有利于管理层投资决策的信息。其次,融资融券对投资-股价敏感性的影响在机构投资者比例高、流动性高、处于新兴行业的这类管理层反馈效应更强的股票组中更显著。参照以往研究考虑了融资约束对反馈效应的调节作用,同样发现融资融券对投资-股价敏感性的影响在国有企业和规模较大的企业组中更显著。最后,融资融券交易规模越大,投资对股价的敏感性越强。     

Determinants of total efficiency in water utilities in Mexico

By using panel data analysis across 368 water utilities in Mexico over the period 2010–2014, we find that small firms are more efficient than medium and large providers and that increasing production is associated with less efficiency. Billing, income collection and profitability are relevant factors to improve efficiency. Medium and large firms require to measure consumption by service with meters in order to increase efficiency, while small firms do not require it.     

给排水工程专业课程体系构造与网页制作

根据给排水工程专业特点,构造给排水专业的课程体系及其相互关系,制作课程体系信息库并应用Frontpage2000软件将其链接起来,在互联网上供本专业学生查阅,达到了指导、帮助学生综合利用自己所学知识进行课程预习、复习及毕业设计的目的.     

国内外水资源承载力的研究综述

随着能源危机的出现,资源环境问题逐渐成为各国经济学家和环境学家特别关注的问题.近年来,水资源短缺越来越成为各地经济发展的制约因素,面对这种情况,资源承载力概念的提出为资源与经济发展问题提供了一条新的研究途径.本文将国内外有关水资源承载力概念和量化方法的研究作一总体分析,结果表明:(1)国外对水资源承载力的研究较少,国内的研究大体可分为初始、发展、鼎盛和拓展四个阶段;(2)从横向比较来看,水资源承载力的研究在我国以近十年为盛.但研究多集中在资源学科领域和地理环境学科领域,角度大多是综合考虑多方面的影响因素,对一个地区的水资源承载力作出系统评价,并借助可持续发展的思想,应用已有的和创新的方法来解决水资源承载力的问题;(3)水资源承载力的研究在一定程度上是土地资源承载力研究的进步;(4)水资源承载力的研究较少考虑环境污染对水资源承载力以及整个社会系统的影响.在此基础上,本文最后对承载力在自然资源方面的研究作了小结和展望.     

Water accounting for the Orange River Basin: An economic perspective on managing a transboundary resource

The framework for water accounting is applied to an international river basin, the Orange River Basin, which is shared among Botswana, Namibia, Lesotho and South Africa. Each of the riparian states faces water constraints and relies increasingly on shared international water resources. The countries have adopted the principle of an economic approach to water management, once basin human needs are met, and all but Lesotho have constructed national water accounts to assist in water management. The water accounts for the Orange River Basin bring an economic perspective to water management at the regional level. The accounts include supply and use tables, which are used to compare the contribution to water supply from each riparian state to the amount used. The water accounts are then linked to economic data for each country to calculate water use and productivity by industry and country. There are considerable disparities in water productivity among the countries, which should be taken into account in future decisions about water allocation, pricing and infrastructure development.     

虚拟水及其在缓解区域水资源短缺中的应用研究

虚拟水是指生产商品和服务所需要的水资源数量。虚拟水战略是指贫水国家或地区通过贸易的方式从富水国家或地区购买水密集型农产品(粮食)来获得本地区水和粮食的安全。本文在综述前人对虚拟水研究的基础上,计算了2002年甘肃省及不同地区主要农产品虚拟水含量,并对甘肃省加强虚拟水贸易的战略进行了探讨。     

Assessment of regional trade and virtual water flows in China

The success of China's economic development has left deep marks on resource availability and quality. Some regions in China are relatively poor with regards to water resources. This problem is exacerbated by economic growth. Flourishing trade activities on both domestic and international levels have resulted in significant amounts of water withdrawal and water pollution. Hence the goal of this paper is to evaluate the current inter-regional trade structure and its effects on water consumption and pollution via ‘virtual water flows’. Virtual water is the water embedded in products and used in the whole production chain, and that is traded between regions or exported to other countries. For this assessment of trade flows and effects on water resources, we have developed an extended regional input-output model for eight hydro-economic regions in China to account for virtual water flows between North and South China. The findings show that the current trade structure in China is not very favorable with regards to water resource allocation and efficiency. North China as a water scarce region virtually exports about 5% of its total available freshwater resources while accepting large amounts of wastewater for other regions' consumption. By contrast, South China a region with abundant water resources is virtually importing water from other regions while their imports are creating waste water polluting other regions' hydro-ecosystems.     

水利与生态环境

本文以实例说明水利建设中缺乏生态环境意识会出现的弊端,提出水利建设的规划、设计、施工、管理全过程都应按生态经济环境水利模式来搞,使我国水利工作进入生态经济环境水利化阶段。     

南水北调中线工程几点思考

本文从四个方面对南水北调中线工程进行了思考:①进行费用效益分析可以使决策更加科学化;②将水资源本身价值纳入经济分析之中实属必要;③需水区节水与调水投资效益比较十分重要;④选择合适的调水时间.对南水北调中线工程决策具有参考价值.