Issues in the analysis of co-authorship networks

Scientific collaboration is a complex phenomenon that improves the sharing of competences and the production of new scientific knowledge. Social Network Analysis is often used to describe the scientific collaboration patterns defined by co-authorship relationships. Different phases of the analysis of collaboration are related to: data collection, network boundary setting, relational data matrix definition, data analysis and interpretation of results. The aim of this paper is to point out some issues that arise in these different phases, highlighting: (i) the use of local archives versus international bibliographic databases; (ii) the use of different approaches for setting boundaries in a whole-network; (iii) the definition of a co-authorship data matrix (binary and weighted ties) and (iv) the analysis and the interpretation of network measures for co-authorship data. We discuss the different choices that can be made in these phases within an illustrative example on real data which is referred to scientific collaboration among researchers affiliated to an academic institution. In particular, we compare global and actor-level network measures computed from binary and weighted co-authorship networks in different disciplines.     

基于成本的物流中心优化设计研究

如何有效地优化物流中心布局设计 ,以便在控制成本的同时提升产品的附加值 ,是众多企业面临的一个共同问题。本文从物流中心设置及配送方案着手 ,提出了相关的优化方法以期解决这一问题。     

On Conditional Density Estimation

With the aim of mitigating the possible problem of negativity in the estimation of the conditional density function, we introduce a so-called re-weighted Nadaraya-Watson (RNW) estimator. The proposed RNW estimator is constructed by a slight modification of the well-known Nadaraya-Watson smoother. With a detailed asymptotic analysis, we demonstrate that the RNW smoother preserves the superior large-sample bias property of the local linear smoother of the conditional density recently proposed in the literature. As a matter of independent statistical interest, the limit distribution of the RNW estimator is also derived.     

On the determinants of data breaches: A cointegration analysis

Decisions in Economics and Finance - Cyber risks and particularly data breaches constitute one of the new frontiers of risk modeling for insurers across the world. We use the cointegration...     

Reaching nirvana with a defaultable asset?

We study the optimal dynamic portfolio exposure to predictable default risk, taking inspiration from the search for yield by means of defaultable assets observed before the 2007–2008 crisis and in its aftermath. Under no arbitrage, default risk is compensated by an ‘yield pickup’ that can strongly attract aggressive investors via an investment-horizon effect in their optimal non-myopic portfolios. We show it by stating the optimal dynamic portfolio problem of Kim and Omberg (Rev Financ Stud 9:141–161, 1996) for a defaultable risky asset and by rigorously proving the existence of nirvana-type solutions. We achieve such a contribution to the portfolio optimization literature by means of a careful, closed-form-yielding adaptation to our defaultable asset setting of the general convex duality approach of Kramkov and Schachermayer (Ann Appl Probab 9(3):904–950, 1999; Ann Appl Probab 13(4):1504–1516, 2003).     

Integrating Environmental,Social and Governance (ESG) Disclosure for a Sustainable Development: An Australian Study

Addressing environmental, social and governance (ESG) issues has become a critical part of business strategy. This article explores the extent of ESG reporting of metal and mining sector companies listed in the Australian Securities Exchange to determine the nature of ESG indicators in use in the sector. The current study argues that stakeholder engagement is the key to enhance company environmental policy and sustainable development. According to the results of this study, ESG reporting motives are highly influenced by reporting regulations. Given the diversity in reporting of ESG, comparability of ESG strategic performance is problematic. This study contributes towards developing an ESG disclosure index, which companies could use as a legitimacy tool that external stakeholders could use to reliably measure and compare the ESG performance of companies. It also reveals there is an increased demand for more empirical research on integration of sustainability into strategic planning process. Copyright © 2016 John Wiley & Sons, Ltd and ERP Environment     

Career Management in High‐Performing Organizations: A Set‐Theoretic Approach

The aim of this study is to investigate the elements of organizational career management (OCM) that can lead to strong organizational performance. The growing unpredictability of careers requires a different organizational approach of careers. Yet, new career models all focus on the individual as the central actor, leaving the role of the organization rather underdeveloped. Based on a combined perspective integrating insights from the literature on careers, high performance work systems, and idiosyncratic deals (I‐deals), we address four dimensions of OCM: supportive and developmental practices, development I‐deals, individual responsibility, and consensus. We study their relationships with company performance, thereby including the firm's human capital composition. Surveys were administered to the HR directors of 293 organizations. We apply a relatively new method, fsQCA (fuzzy‐set qualitative comparative analysis), and complement this with more conventional structural equation modeling (SEM). The SEM analyses suggest that only supportive and developmental practices are positively associated with high performance. However, based on the fsQCA, three configurations are identified in which OCM is associated with high performance. The most prevalent configuration combined supportive and developmental practices with I‐deals and individual responsibility for career management. We conclude with a discussion of the implications of our findings, and address the utility of adopting a configurational approach in career research. © 2016 Wiley Periodicals, Inc.     

Flexible Working,Individual Performance,and Employee Attitudes: Comparing Formal and Informal Arrangements

In the context of a wider trend to individualize human resource management, this article examines the relationship between flexible working arrangements and individual performance. Drawing on a range of theories, this article also examines potential indirect effects on employee performance via job satisfaction and organizational commitment and analyzes whether these relationships vary according to whether the arrangement was set up through a formal process or negotiated informally between the employee and his or her line manager. Extant research has tended to focus on formal arrangements, however, informal arrangements are widespread and may better accommodate work‐life preferences, thereby potentially fostering more positive attitudes from employees. Survey data from 2,617 employees in four large organizations with well‐established flexible working policies are analyzed. Results from structural equation models show average positive indirect effects from informal flexible working, but also negative direct effects from formal flexible working. When two forms of flexible working amenable to being set up by both formal and informal means are examined separately, formal arrangements for flexibility over working hours are found to be negatively associated with performance, but also a source of greater job satisfaction; informal remote working arrangements have positive indirect effects via organizational commitment and job satisfaction on worker performance. © 2016 Wiley Periodicals, Inc.     

Organisational consequences of asymmetries in task dependence: the moderating role of HR practices

This study integrates recent advances in interdependence theory with the literature on commitment‐based HR practices. New research on interdependence theory suggests that differences, or asymmetries, in task dependence among organisational members can cause interests to diverge. Prior research has shown that this can negatively affect interpersonal relations, individual outcomes and team processes. However, these insights gained on the dyadic, individual and team levels of analysis have not yet been explored at the organisational level and, until now, no research had yet connected these advances in interdependence theory to the field of HRM research. Hence, the current study investigates (a) whether asymmetries in task dependence do (or do not) matter at the organisational level and affect organisational effectiveness, (b) why this relationship may work by assessing a key mediator, namely, trust climate and (c) if and how these relationships can be altered by commitment‐based HR practices. Our moderated‐mediation model was tested and fully supported by a multi‐source data set of 8,390 employees from 67 organisations.     

Technical Efficiency of the Brazilian Municipalities: Correcting Nonparametric Frontier Measurements for Outliers

In this paper we estimate the DEA technical efficiency for 4796 Brazilian municipalities, by applying a recently proposed “Jackstrap” method, which combines Bootstrap and Jackknife resampling techniques, to reduce the effect of outliers and possible errors in the data set. We perform calculations to identify and eliminate high leverage municipalities, using different variants of Data Envelopment Analysis (DEA), as well as Free Disposal Hull (FDH). Corroborating previous results, efficiency results for the Brazilian municipalities show a clear relationship between the size of the municipality and its efficiency scores. Indeed, under both DEA variants, smaller cities tend to be less efficient than larger ones hence indicating that the quality of the frontier adjustment improves significantly as the size of the municipality increases. We present arguments that may explain to some extent these findings, such as economies of scale and the excess spending due to revenue from royalties. However, such effects require further, more careful examination.