Applying free random variables to random matrix analysis of financial data. Part I: The Gaussian case

We apply the concept of free random variables to doubly correlated (Gaussian) Wishart random matrix models, appearing, for example, in a multivariate analysis of financial time series, and displaying both inter-asset cross-covariances and temporal auto-covariances. We give a comprehensive introduction to the rich financial reality behind such models. We explain in an elementary way the main techniques of free random variables calculus, with a view to promoting them in the quantitative finance community. We apply our findings to tackle several financially relevant problems, such as a universe of assets displaying exponentially decaying temporal covariances, or the exponentially weighted moving average, both with an arbitrary structure of cross-covariances.     

Beyond brand loyalty: Brand sustainability

Historically, measures of brand value have focused on brand awareness, customer brand equity and measured brand loyalty. While useful, these generally provide little visibility for the future of the brand. A new measure, brand sustainability, is proposed, described and illustrated. Drawing on over 1 million responses to online customer questionnaires, over a 10-year period, covering brands in 73 FMCG product categories, we create, illustrate and demonstrate a brand sustainability measure. That measure consists of brand share of preference, a calculation of their average annual growth rate. That is then compared to the consumer-stated no brand preference in that category. Net promoter scores are used to support those calculations. Findings show that manufacturer brands are challenged, not by private label, but by no brand preference in the category. Research suggestions are made on how to develop and use brand sustainability and the impact of that measure on future brand growth and development.     

Financial Times Business School Rankings: A Nontraditional Assurance Case in Three Parts*

The Financial Times of London (FT) is a business newspaper, with daily editions published in the United Kingdom, continental Europe, the United States, and Asia, and an estimated daily readership of 10 million people. In 1999 the FT began to publish a ranking of what it considered to be the top business schools in the world. Since their inception, these rankings have become increasingly relied upon by potential students and business school administrators worldwide. The FT's ranking is unique compared with other rankings because of its special international focus. Given the prominence of these rankings and the FT's position as a well‐respected business newspaper, the question of providing assurance over the business school rankings that the FT provides is particularly challenging.     

保险欺诈防范研究与思考

在我国保险欺诈问题日趋严重的背景下,本文通过博弈论理论以及matlab等软件进行回归预测模型的构建,对国际上在反保险欺诈领域领先的国家采取的措施及其经验进行了定量分析。同时,结合我国国情,提出解决我国保险欺诈问题的建议。     

解决农民工工资拖欠问题的思考

本文认为,近年来我国农民工工资拖欠问题日益严重,已成为影响劳动关系和谐发展乃至社会稳定的重要因素。当前解决农民工工资拖欠问题的模式主要有两大类,即行政机关采取行政手段的讨薪模式和劳动仲裁委员会及司法机关采取劳动仲裁和法律诉讼手段的讨薪模式,这些模式都存在一定的缺陷。考虑到工会在解决农民工工资拖欠问题方面的优势,应完成工会从行政化向市场化的转型,创新工会工作方式,赋予工会运用有利于开展工作的法律手段的权力,通过工会加强和提高农民工自身力量,从而形成解决农民工工资拖欠问题的长效机制。     

同城与异地对冲动性购买行为的影响研究

异地冲动性购买在商场和超市占有相当大的比例,现有的文献对同城冲动性购买进行了大量的研究,然而对异地冲动性购买研究较少.在这些理论基础上,通过访谈与问卷调查形式,分析了影响同城与异地冲动性购买行为的因素,并比较消费者在同城与异地发生冲动性购买行为的因素的异同以及产生这些异同的原因,提出了企业需要采取的营销措施.     

Store and store format loyalty measures based on budget allocation

In highly competitive environments, such as retail markets, characterized by a growing heterogeneity of demand and the proliferation of new retail formats, cross-shopping behavior between stores and formats is becoming increasingly common. This process makes customer loyalty a key strategic challenge for retailers that want to consolidate their position within the market. To contribute to the analysis and comprehension of this reality, the authors propose and assess different objective indicators of store loyalty, store format loyalty, and intra-format store loyalty based on budget allocation. Specifically, they analyze the role of retail format in observable loyalty patterns in a market. Through an empirical analysis of grocery purchase patterns of a sample of 580 Spanish households, the authors find that diverse objective loyalty indicators based on budget allocations provide very similar information from a practical point of view. They also find that consumers' regular use of various formats (specifically, supermarkets, hypermarkets, and discount stores) for their purchases explain observed disloyalty better than does purchasing in several stores within these formats. The observed patterns reveal that retail formats define differentiated store profiles that relate to the benefits sought in different purchase situations.     

我国企业信息化现状与改革措施

我国企业在信息化进程取得了一定的成绩,但仍存在问题,在此基础上,应明确我国企业信息化的总体发展思路,加速我国企业信息化的建设。     

A response to the critiques of DEA by Dmitruk and Koshevoy, and Bol

We here critique the articles by Dmitruk & Koshevoy (1991, J Econ Theory 55:121–144) and by Bol (1986, J Econ Theory 38:380–385) by showing how to solve the examples they erected to show the non-existence of functions for evaluating performance efficiencies in DEA. We also show that functions satisfying these criteria—and other important criteria as well—were already available prior to the publications of D&K and by Bol and have since been greatly extended to increase the power and scope of DEA.

“免疫系统”理论视野下的国家审计

"免疫系统"理论的形成与提出是审计理论的创新,在今后相当长的一段时期内具有理论研究价值和现实指导意义.在"免疫系统"理论新视野下,国家审计应在借鉴免疫系‘统的自发性和自适应性的基础上,确保其独立性和强制性,完善审计机制;发挥防御、自稳、监督职能和防护性、建设性、调控性等作用,维护国家安全.作为经济社会运行中的"免疫系统",国家审计的内在机理是及时发现问题、依法处理问题、充分利用成果、依法报告工作.而不断增强并充分发挥国家审计的"免疫系统"功能的措施有:积极探索务实高效和充分保障审计独立性的体制机制;努力完善国家审计联系制度和审计结果公开制度;持续改进各部门的协调机制及国家审计的创新机制;大力加强基础建设,夯实可持续发展的根基.