An elastic-net penalized expectile regression with applications

To perform variable selection in expectile regression, we introduce the elastic-net penalty into expectile regression and propose an elastic-net penalized expectile regression (ER-EN) model. We then adopt the semismooth Newton coordinate descent (SNCD) algorithm to solve the proposed ER-EN model in high-dimensional settings. The advantages of ER-EN model are illustrated via extensive Monte Carlo simulations. The numerical results show that the ER-EN model outperforms the elastic-net penalized least squares regression (LSR-EN), the elastic-net penalized Huber regression (HR-EN), the elastic-net penalized quantile regression (QR-EN) and conventional expectile regression (ER) in terms of variable selection and predictive ability, especially for asymmetric distributions. We also apply the ER-EN model to two real-world applications: relative location of CT slices on the axial axis and metabolism of tacrolimus (Tac) drug. Empirical results also demonstrate the superiority of the ER-EN model.     

Outlier detection and robust variable selection via the penalized weighted LAD-LASSO method

This paper studies the outlier detection and robust variable selection problem in the linear regression model. The penalized weighted least absolute deviation (PWLAD) regression estimation method and the adaptive least absolute shrinkage and selection operator (LASSO) are combined to simultaneously achieve outlier detection, and robust variable selection. An iterative algorithm is proposed to solve the proposed optimization problem. Monte Carlo studies are evaluated the finite-sample performance of the proposed methods. The results indicate that the finite sample performance of the proposed methods performs better than that of the existing methods when there are leverage points or outliers in the response variable or explanatory variables. Finally, we apply the proposed methodology to analyze two real datasets.     

Labour Market Institutions and Flexibility in Italy

ABSTRACT: The paper surveys three broad categories of labor market institutions in Italy: employment protection legislation unemployment benefit systems and wage bargaining arrangements In each we the recent evolution and current state of Italian institutions are evaluated and compared With those in other major European countries     

The Role of Interorganizational and Organizational Factors on the Decision Mode for Adoption of Interorganizational Systems*

The dramatic growth of interorganizational systems (IOS) has changed the way organizations conduct their business, and has resulted in significant tangible and intangible benefits being realized by participating firms. However, the implementation of these IOS requires the cooperation and commitment of all the participating members. These members may have complex economic and business relationships among themselves that can result in a number of social, political, and economic factors influencing the adoption and implementation of IOS. This study examines the role of interorganizational and organizational factors on the decision mode for adoption of IOS, in the specific context of electronic data interchange (EDI). Four interorganizational factors, based on the socio-political framework derived from research in marketing, and five organizational factors based on research in IS were used in the study. The data for the study were collected through a large scale field survey. Two respondents, the sales/purchase manager and the IS manager, from 201 firms responded to the survey. The results of discriminant analysis of the data reveal that two interorganizational variables, competitive pressure and exercised power, and two organizational variables, internal need and top management support, are important variables to differentiate firms with proactive decision mode from firms with reactive decision mode. The study also evaluates the differences between proactive and reactive firms on three implementation outcomes. Proactive firms are found to have greater extent of adaptation, more external connectivity with trading partners, and better integration of EDI information in their internal IS applications.     

Decisions to Outsource Information Systems Functions: Testing a Strategy-Theoretic Discrepancy Model

In recent years, the decision to outsource information systems (IS) functions has become a viable strategic alternative in managing the increasingly complex IS functions. In this study, the IS outsourcing phenomenon is conceptualized as a strategic decision in the organization. Drawing on resource-based theories, resource dependence theories, and other theories of strategic management, a discrepancy model of this decision is developed. Relationships between a number of strategy-theoretic factors and the IS outsourcing decision are hypothesized. These factors include IS resource performance discrepancies manifested in the form of gaps in information quality, IS support quality, IS cost effectiveness and financial performance, as well as the strategic orientation of the firm. Results of the study indicate that, while cost consideration and the firm's financial performance are not associated with the IS outsourcing decision, difficulties in providing good information outputs and IS support services are associated with the decision. Overall, the findings suggest that the current trend toward outsourcing represents a continuing evolution of the IS function as it attempts to fulfill its traditional mission of providing high quality information resource to the firm. When the performance of the delivered resource begins to slip in the current environment of rising expectation and technological complexity, outsourcing may become a strategic response of necessity. The paper concludes with a discussion of the implications of the results for practicing managers and suggestions for future research.     

Vendor Selection with Bundling*

Product bundling has become increasingly prevalent not only in consumer goods but also in the industrial sector. We study a purchasing problem in which a buyer must obtain necessary numbers of various stock items from a variety of vendors who charge different prices, have limited capacities and different levels of quality, and offer bundled products at discounted prices. We examine relationships among different bundling scenarios and show that the most general scenario is one in which free items are given to the buyer when sufficient quantities are purchased. We develop a mixed integer linear program that finds the purchasing strategy for the buyer that minimizes the total purchase cost. We present computational results which indicate that the problem is very tractable to solve optimally on a personal computer with standard optimization software. Finally, three extensions of the model are discussed.     

A Path Analytic Model of a Theory of Quality Management Underlying the Deming Management Method: Preliminary Empirical Findings*

Despite the impact that Deming and his 14 Points have had on the practice of quality management, empirical support for the effectiveness of the Deming Management Method has not advanced beyond the presentation of anecdotal, case-study evidence. In part, this is because theory to guide the conduct of empirical research has not been available. Only recently has such a theory of quality management to describe and explain the effectiveness of the Deming Management Method been articulated in the literature. This paper continues the journey of theory development; it reports the results of an exploratory empirical analysis of an articulated theory of quality management underlying the Deming Management Method. The constructs in the proposed theory are operationalized using measurement statements developed by the World-Class Manufacturing research project team at the University of Minnesota and Iowa State University. Path analysis is applied to the World-Class Manufacturing project data to explore the empirical strength of relationships advanced in the theory. The path analytic results provide support for several of the proposed relationships in the theory, and more importantly, suggest a number of new relationships which have not heretofore been proposed.     

建构大众传播学新型主体的力作--评《采访对象主体论》

美国新闻学家杰克·海敦说过:“新闻事业是一个跟人打交道的行业。大约99%的新闻是部分或全部以访问——也就是向人提问题——为基础写成。”作为消息源的采访对象是新闻信息的承载者,是大众传播的一传手,在新闻传播过程中有着特殊而又极其重要的地位与作用。在中外新闻采访学中采访对象仅是记者从事采访活动的客体,而在大众传播学中,没有“采访对象”这一概念,只是作为一种“信息源”被提及。广西大学新闻系副教授靖鸣的论著《采访对象主体论》将采访对象提升到大众传播学研究体系中重要的主体地位来研究,试图构建一个全新的科学合理的大众…     

观照哲学基本问题的思想境域

通常的理解,哲学的基本问题就是思维与存在的关系问题。其实,思维与存在能够发生关系,成为矛盾,却在于作为其潜在前提的某种思想境域。哲学基本问题在哲学史中的连续演绎也是思想境域的不断转换。     

近代广东商业人群在广西的分布面及其梯度差考详——粤港商业经济对广西经济辐射研究之二

文章从中国近代史上城镇经济主体——商业经济的角度切入,运用各类历史资料,分区逐县地确证广东商业人群以及所造成的“无东不成市”格局在全广西的分布范围,并揭示其在广西不同地域的程度等差和梯度分布状态。从而,以原始的生活场景原生态地呈现出粤港澳地区对广西经济辐射由东而西逐步推进、由城市而圩市逐层次渗透的基本节奏和客观规律。