International portfolio selection and efficiency analysis

In the risk-return tradeoff, the traditional mean-variance analysis has been widely used for studies of international portfolio efficiency and diversification. Without prior knowledge about either the parametric structure of assets' return distributions or the form of investors' preference functions, the variance may no longer serve as a suitable risk proxy. This article examines international portfolio efficiency and diversification effects through mean-variance and various distribution-free (or less restrictive) risk-return measures. We show empirically that the mean-variance model is appropriate for large or well-diversified portfolios, but may provide biased results for single assets and less diversified portfolios. While stochastic dominance stands as theoretically the most appropriate method of international portfolio selection and efficiency analysis, the lack of optimal search algorithms reduces its practical usefulness. Very little gain is obtained by using the Gini-mean-difference risk measure as compared to the semivariance measure. The semivariance measure is a powerful and convenient discriminator of risky prospects, while stochastic dominance can serve as a benchmark to justify portfolio efficiency.     

甘肃省改革开放成就回顾与展望

改革开放,甘肃省经济社会取得了前所未有的发展进步,但因资源、环境、体制、人才、科技、观念等特殊省情的限制,其发展在历史和当今都落后于其他省份,也产生了很多不足和问题。事物发展是个矛盾体,也是前进性和曲折性的统一,面对37年的辉煌和阻力,中央、省委省政府、普通公众只有同心协力,才能创造甘肃省更好的明天。     

生成树协议在局域网中的应用

生成树协议是一种二层管理协议,它通过有选择性地阻塞网络冗余链路来达到消除网络二层环路的目的,同时具备链路的备份功能。生成树协议因为能在局域网中构建无环路的逻辑拓扑结构和提供较强的网络容错功能,而在局域网的可靠性设计中得到广泛应用。论文简要介绍了局域网可靠性设计的思想和生成树协议的工作原理,重点描述了STP在交换机中的实现。     

Potential and recognized boundary spanners in multinational corporations

Boundary spanners play an important role in multinational corporations (MNC), yet it is unclear who these valuable individuals are and why certain individuals, and not others, perform this role. We advance a ‘recognition’ perspective based on whether and how relevant others on both sides on the boundary experience positive impact. A dynamic integrated mixed method analysis of 118 individuals involved in headquarters-subsidiary interactions in four MNCs, shows that only a minority are ‘recognized boundary spanners’, experienced by others to positively impact intergroup relations. We identify different categories and mechanisms of recognition, and make a methodological contribution by integrating qualitative and quantitative analysis.     

How optimal distinctiveness affects new ventures' failure risk: A contingency perspective

In this article, we apply the concept of optimal distinctiveness to test whether category spanning has a nonlinear effect on new ventures' risk to fail. We argue that by being optimally distinct, i.e., by attaining a level of category spanning that allows new ventures to benefit from balancing the competing needs of conformity with and differentiation from competitors, new ventures can improve their survival chances. In addition, we argue that the relevance of optimal distinctiveness varies with a venture's age and a category's density. We tested our hypotheses using data from 1668 metal bands that were founded in the United Kingdom between 1967 and 2005. The results indicate that optimal distinctiveness is relevant to new ventures' failure risk. Moreover, we show that venture age attenuates the relevance of optimal distinctiveness, whereas category density strengthens that factor's relevance.     

最大熵原理在证券投资组合中的应用研究

为了解决马科维茨(Markowitz)模型中以证券收益率的方差测度投资风险的局限性,本文提出了利用最大熵原理建立证券投资组合优化模型。并用该模型进行了实例分析,结果表明,比均值-方差模型可获得更高的收益。     

创业型企业跨界创新模式建构与实现路径

外部环境的不确定性会激发企业进行开放式创新,跨界创新作为开放式创新的一种形式,是小微创业企业实现跨越式发展的有效途径。基于跨界搜索视角,应用SPS案例研究法进行相关资料收集与分析,初步构建了小微创业企业跨界创新模式框架。通过跨界搜索知识、科学技术和社会关系,实现不同维度跨界战略与跨界能力组合式协同提升,是企业实现跨界创新的有效模式,也是小微创业企业不断创新的作用机制。     

Industrial sales people as market actors

We develop the concept of boundaries in the context of sales personnel and their counterparts encountering and negotiating these while they undertake work to shape markets and build relationships. Drawing on a case study from production chemistry, we show that market shaping implies a mutual development of relationships, goods and services exchanged, and boundaries. In particular, we show that while relationships can submerge and obscure parts or dimensions of boundaries to other market actors, normal business activities such as testing new products and adapting products to changes in environmental legislation make visible some material dimensions of the exchange object, which can attract attention from other sellers. Visibility finds an expression as those market objects are exchanged, such that objects can be devices by which other actors join in and position themselves and their objects within markets.     

An Interpretation of SDF Based Performance Measures

This note discusses stochastic discount factor (SDF) measuresof mutual fund performance. It shows that the most common SDFperformance measures can be interpreted as Jensen's "alphas".JEL Classification Numbers: G11, G12, G23     

Variance Vulnerability, Background Risks, and Mean-Variance Preferences

An agent with two-parameter, mean-variance preferences is called variance vulnerable if an increase in the variance of an exogenous, independent background risk induces the agent to choose a lower level of risky activities. Variance vulnerability resembles the notion of risk vulnerability in the expected utility (EU) framework. First, we characterize variance vulnerability in terms of two-parameter utility functions. Second, we identify the multivariate normal as the only distribution such that EU- and two-parameter approach are compatible when independent background risks prevail. Third, presupposing normality, we show that—analogously to risk vulnerability—temperance is a necessary, and standardness and convex risk aversion are sufficient conditions for variance vulnerability.