How to measure mutual fund performance: economic versus statistical relevance

In the present paper a comprehensive assessment of existing mutual fund performance models is presented. Using a survivor‐bias free database of all US mutual funds, we explore the added value of introducing extra variables such as size, book‐to‐market, momentum and a bond index. In addition to that we evaluate the use of introducing time‐variation in betas and alpha. The search for the most suitable model to measure mutual fund performance will be addressed along two lines. First, we are interested in the statistical significance of adding more factors to the single factor model. Second, we focus on the economic importance of more elaborate model specifications. The added value of the present study lies both in the step‐wise process of identifying relevant factors, and the use of a rich US mutual fund database that was recently released by the Center for Research in Security Prices.     

Estimation of the mean in ranked set sampling with non responses

The estimation of the population mean when ranked set sampling [rss] is used for selecting the sample and non responses [nr] are present, is studied. The nr stratum is sub sampled using simple random sampling with replacement. Two strategies are analyzed. One of them is based on the selection of a sub sample from the nr in each cycle. The other uses sub samples selected among the nr in each rank.  The accuracy of the proposed estimators is characterized by the corresponding expected variances. Simulations and real life data are used for analyzing the behavior of them. Acknowledgements: This paper was developed partially during the visit of the author to Université des Antilles et Gouyane. The author gratefully acknowledges the helpful suggestions of the referees and thanks the support of DAAD for visiting Humboldt University where a version of the paper version was made.     

中国农村金融组织生存、变迁及发展

由于农业的弱质性及在国民经济发展中的基础地位，农村金融组织在农村经济及整个国民经济稳定发展中发挥着不可或缺的作用。中国农村金融组织也有一个生存、发展的制度变迁过程。本文在研究了合作经济及农村金融组织在农村经济发展中的作用的基础上，重点研究了法国的农村金融体系在法国国民经济中的作用，并进一步探讨了中国农村金融组织的生存条件、制度变迁及发展。     

Efficiency outcomes of market concentration and managed care

The paper examines how hospital cost efficiency has reacted to extensive horizontal integrations of hospitals and rapid growth of managed care in the US health care industry. Cost efficiency is estimated by using panel data approaches to relax the assumptions for the hospital effects imposed in earlier studies. The paper shows that higher managed care penetration over time is associated with greater hospital efficiency, and higher market concentration is positively associated with efficiency when markets are highly competitive or highly concentrated.     

Does price reflect emotional,structural or performance quality?

Three denim jeans products from the same manufacturer with differentiated pricing and labels (antiqued, sandblasted, and stonewashed) were used to determine the relationship between price and quality. Both qualitative and quantitative procedures were used to analyse the garments. All three jeans were made of twill weave with 3 × 1 repeat. Both structural and performance characteristics were compared using standardized tests. Analysis of variance was used to compare the selected structural and performance characteristics among the three jeans products. Tukey’s HSD tests were used for post hoc multiple comparisons for three jeans. The findings revealed that despite the fact that all three jeans products were from the same store, and that the fabrics used the same weave, degree and direction of twist, the jeans differed significantly for several structural and performance characteristics. Several possibilities for future research were explored.     

Measuring the Impact of Regulation: A Study of Canadian Basic Cable Television

We evaluate the appropriateness of regulation within the Canadian cable television industry by applying both parametric and non-parametric approachesto measure scale efficiency. Although we begin with a sample offering adequatedegrees of freedom for parametric estimation, important policy issues lead us toconsider further estimation over sub-samples. Since some of these sub-samplesare small enough that parametric models cannot guarantee reliable estimates, weobtain production characteristics non-parametrically through data envelopmentanalysis. The nonparametric results for scale efficiency support the parametricresults. We find evidence against a natural monopoly argument that might havejustified continuation of the mandated monopolization of Canadian cable televisionservice. By the end of the sample period, there were no longer substantial economiesof scale in most relevant markets.     

Learning in Design and Technology: The Impact of Social and Cultural Influences on Modelling

The paper introduces the highly problematic nature of modelling in design and technology education and examines the relationship between cognitive and concrete modelling. Its aim is to gain insight into what learners do, rather than what others say they ought to do in their learning activities. The variety of purposes that educators have for learners’ modelling are discussed through examining the contested curriculum justification for design and technology education itself. The paper proposes that learners’ modelling cannot be extracted from the social milieu in which they act and it provides some insights of these social influences through the analysis of two case studies. Their settings are a girls’ secondary school and a college of higher education. Each case study is presented independently but organised with a common format to consider a) the impact of assessment on learning intentions and outcomes; b) cultural influences on learning and modelling; c) social influences on learning and modelling. A discussion of the emergent themes considers implications for teachers. This revised version was published online in July 2006 with corrections to the Cover Date.     

Finding Pareto Optimal Insurance Contracts

This paper deals with on-line computation—or step-wise learning—of Pareto optimal insurance contracts. Our approach tolerates that the loss distribution might be unknown, intractable, or not well specified. Thus we accommodate fairly inexperienced parties. Losses are here simulated or observed, one at a time, and they cause iterated revisions of the premium. The mechanical and global nature of probability calculus thereby yields to more tentative, myopic procedures, possibly closer to how humans operate or reason in face of risk. Sequential revisions may also reduce the expense of insurers' time and money in seeking sufficient statistics. Emphasized below is the remarkable simplicity and stability of the resulting adaptive procedures. Special attention goes to catastrophic risks, and to subsidized or competitive insurance.     

工作本位学习理论的系统分析

工作本位学习是基于从学校到工作岗位(school-to-work)的理念下提出来的,试图整合学习策略和工作实践,促进学习者的学习,以更好适应工作的需要。工作本位课程理论是在上述理念基础上开发出来的,对我国高职教育提供有益的启示。     

Urban Influence on Costs of Production in the Corn Belt

This article determines the relative technical efficiency of rural- and urban-influenced crop/livestock enterprises in the Corn Belt. Farmers in urban-influenced locations are less technically efficient than farmers in rural locations. During 1998–2000, stochastic production frontier procedures indicate that a 10% increase in urban influence leads to a close to 4% decrease in technical efficiency. The most successful urban-influenced farms have controlled costs as effectively as rural farms. They have tended to de-emphasize that nondairy livestock activities—particularly beef and hogs—do not rely extensively on off-farm income, and have relatively large, less residential/lifestyle operations compared to less successful urban-influenced farmers. However, our statistical analysis clearly bears out the refrain in popular literature that urban proximity raises the cost for, and decreases the viability of, traditional farms.