Real estate return correlations: Real-world limitations on relationships inferred from NCREIF data

Correlation estimates for returns between individual properties are subject to large inherent uncertainties due to limits on the amount of data that is likely to be available for the foreseeable future. After allowance for correlation sampling error, it is impossible to distinguish on an ex ante basis between the risk-reduction capabilities of mean-variance portfolio selection models and naive diversification without regard to property type or geographical location. The naive portfolio diversification strategies of typical institutional real estate portfolio managers are rational responses to limitations on the informational content of statistical analyses of historical real estate data.     

制度互补与电力市场化改革

我国电力改革选择了从发电环节的改革开始，经重组国家电力公司、实行厂网分离，到实行电价改革的渐进式策略。这一策略虽然因其速度缓慢、终端用户无法分享改革利益而备受批评，但它使社会付出了较低的“无序成本”。随着供求关系的缓解．电力产业应强化制度互补作用，尽快改变改革在发电、输电、配电、售电各个环节之间进展不平衡的状况，着力实现配电和售电分离。在售电环节引入竞争机制．探索与市场化改革相适应的监管体制和交易方式，解决电源结构不合理、电力发电输电配电效率低、负外部性等深层次问题，最终建立有效监管的电力市场．使市场在电力资源的配置上发挥更大作用。     

我国煤炭输送方式经济性方面的研究工作

煤炭运输方式的经济性问题是制定能源产业政策的基本理论问题之一,为此回顾了我国五十年代以来的部分有关研究工作,对不同时期的部分研究实例从研究方法、技术方案和研究结论三个方面进行了对比分析,揭示了不同研究工作在基本原理方面的一致性和技术方案方面的差异性,以及由此造成的研究结论的异同。     

加强无功电压管理 降低电网线路损耗

从石河子电网(文中简称石网)无功电压的运行现状及线损率的变化规律出发,分析了无功电压对电网经济运行的影响,并从技术、经济、管理三方面提出如何加强无功电压管理、降低电网线路损耗的建议.     

电网企业优化购电成本方法研究与实证分析

通过购电成本结构分析,指出了当前发电计划编制及执行中存在的问题和当前发电计划编制对电网购电费的影响。重点研究了有关降低电网购电成本的方法及实证,并为政府价格相关部门提出创建节能型社会的政策建议。     

Reduced Tax Progressivity in Norway in the Nineties: The Effect from Tax Changes

The inequality in pre-tax income increased in Norway in the 1990s, while the concentration of taxes remained largely unaltered. This means that tax progressivity has decreased in the period, as measured by summary indices of tax progressivity. In this paper I analyze individual income data to ascertain whether tax changes in the period can explain the observed decrease in tax progressivity. As marginal tax rates at high income levels have been substantially reduced in the period, for instance through the tax reform of 1992, it is expected that tax changes may have influenced the degree of inequality in pre-tax incomes. This behavioral effect is examined by deriving estimates of the elasticity of gross income with respect to the net-of-tax rate, obtained from various panel data regressions. The tax changes may also have shifted the distributional burden of taxes for unaltered level of pre-tax income inequality. In order to identify this (direct) effect of tax-law alterations, the same fixed distribution of pre-tax income is exposed to various tax-laws in the period.     

A multilateral approach to examining the comovements among major world equity markets

This study investigates the comovement in stock indices among major developed markets, where Morgan Stanley Capital International (MSCI) indices are employed for the purposes of the study. We employ a model that accommodates multilateral international impacts on equity index movements. The empirical results reveal the existence of significant international transmission effects among these major world markets, both in terms of returns and volatility, and mostly in a positive direction. The U.S. market, as expected, is the leading market in the sense that it has the most pervasive and significant impact on all markets across continents. However, the U.S. market exhibits a different relationship with European markets from that with Asia-Pacific markets. The evidence also suggests that strong regional transmission effects exist. A further investigation using the extended model reveals that the linkages between U.S. and European markets are driven by positive global common forces and by negative international competitive effects. On the other hand, the U.S. and Asian markets are linked through positive global common forces and positive international contagion effects. The United States, Canada, and the U.K. are the three markets that still demonstrate contagion influence over countries outside its own region. The Asia-Pacific markets are more susceptible to contagion effects. Finally, it is interesting to find that Japanese market performance became more contagious toward other markets during the Asian financial crisis period.     

aecXML与STEP在建筑业信息集成中的应用

利用Web实现建筑业信息集成是建筑业信息化的发展方向，而平台的不统一性和数据的异构性是信息集成化发展的瓶颈。综合运用aecXML和STEP技术实现信息的标准化传递，可以克服这个问题。章介绍了aecXML和STEP的基本概念及其各自的优缺点，探讨了基于aecXML和STEP的建筑产品数据共享和交换结构模型，以及基于aecXML的建设项目信息共享与交换结构模型，并对两种技术的综合应用前景进行了展望。     

西气东输工程用大口径X70级螺旋埋弧焊钢管的力学性能研究

以大量生产检验数据,对西气东输管线的力学性能进行了综合研究,并对其受包申格效应的影响情况进行了分析.     

关于输配电价几个重要问题的探讨

我国电力企业将要由传统的垂直垄断的模式转变为网厂分开、竞价上网的模式。电网公司作为一个独立的经营实体分离开来,有着独立的收益需求。在市场运营过程中,通过输配电价取得收益就成了电网公司取得收益的主要手段。在输配电价的制订过程之中,管制方式、输配电成本、输电定价方法、价格水平及电网投资、输配电价价区、电网提供的辅助服务等六个问题十分重要。文中就这六个问题的解决作了一些有价值的探讨。