Sul tasso implicito di operazioni finanziarie aleatorie

Si danno limitazioni inferiori e superiori per il valor medio del tasso implicito di operazioni finanziarie aleatorie di una classe determinata. Per l’ottenimento di alcune disuguaglianze si fa uso di una versione generalizzata della ben nota disuguaglianza di ?eby?ev tra medie con diverse ponderazioni che viene dimostrata in appendice e che vale anche per distribuzioni di probabilitá con componenti discreta e continua congiuntamente.     

Managerial Sharing,Mutual Fund Connections,and Performance

In this study, we examine the effect of mutual fund connections, through managerial sharing, on performance and stock holding commonalities. Our analysis of return correlations and portfolio holdings indicates that more interconnected funds tend to buy and sell similar stocks, hence increasing the similarity of portfolio holdings and undermining the distinctiveness of their investment strategy. Our results also indicate that highly connected funds significantly underperform weakly connected funds by about 1.4% on a yearly risk‐adjusted basis. We show that fund family performance is unaffected by the intensity of fund connections, and that greater fund connections could significantly enhance family‐level profit margins.     

Reverse mortgages through artificial intelligence: new opportunities for the actuaries

Decisions in Economics and Finance - In its basic structure, the reverse mortgage (RM) is a contract where a home owner borrows a part or the totality of the future liquidation value of his home at...     

Who benefits from privileged peers? Evidence from siblings in schools

By comparing siblings attending the same school at different points in time, we investigate whether the effect of peer quality on long-term labor market outcomes varies with parental background. We find that exposure to better peers—who have higher mean parental education—increases lifetime earnings of disadvantaged students, coming from families with low parental education, but penalizes privileged students from better educated families. These results suggest that desegregation policies that allocate disadvantaged students to schools with better peers produce long-term benefits. We discuss mechanisms and show that human capital accumulation, ordinal rank and network effects contribute to explain our findings.     

Services as drivers of economic growth. Is there an opportunity for Latin America countries?

ABSTRACT

Considering the recent improvements in services innovation and productivity performance, the aim of the article is to analyze if they can act as a new growth driver for Latin American countries. For that, we review the literature on services and structural change in two stages. First, we apply a bibliometric methodology to identify the main trends in literature. Second, we analyze in-depth a smaller set of papers in order to extract the main lessons regarding three aspects of our question: (i) services and productivity growth, (ii) new opportunities for innovation in services and (iii) relation between services and manufacturing through servitization process. The results show that productivity and innovation growth in services are concentrated in only a few branches. Besides this, services performance depends on their links with manufacturing activities. We conclude that the current Latin American servitization process clausure opportunities for developing instead of opening them.     

Analytic derivatives and the computation of GARCH estimates

In the context of univariate GARCH models we show how analytic first and second derivatives of the log-likelihood can be successfully employed for estimation purposes. Maximum likelihood GARCH estimation usually relies on the numerical approximation to the log-likelihood derivatives, on the grounds that an exact analytic differentiation is much too burdensome. We argue that this is not the case and that the computational benefit of using the analytic derivatives (first and second) may be substantial. Furthermore, we make a comparison of various gradient algorithms that are used for the maximization of the GARCH Gaussian likelihood. We suggest the implementation of a globally efficient computation algorithm that is obtained by suitably combining the use of the estimated information matrix with that of the exact Hessian during the maximization process. As this would appear a straightforward extension, we then study the finite sample performance of the exact Hessian and its approximations (that is, the estimated information, outer products and misspecification robust matrices) in inference.     

The problem of employees' network centrality and supervisors' error in performance appraisal: A multilevel theory

This article reveals an unexplored paradox for HR managers: the centrality of an employee in the social network benefits performance but hampers performance appraisal because it affects supervisors' rating errors. Central employees can be erroneously rated high on performance even when they are not high performers because supervisors tend to overappraise their performance. A distinction is made between rating precision, which depends on supervisors' uncertainty regarding employees' performance, and rating accuracy, which depends on supervisors' bias in favor of employees. Employee centrality is posited to be beneficial to precision but deleterious to accuracy because it regulates the diffusion of positive information, status, and power, all of which distort supervisors' capacity and motivation to accurately appraise performance. It is then argued that rating errors caused by network centrality affect aggregate perceptions of justice in organizations. When employees are highly connected to each other in a dense network, organizations have a strong and positive justice climate. Yet when some employees are more central than others in a centralized network, organizations have a negative and weak justice climate. The article contributes to the literature because it identifies an unexplored dark side of network centrality and offers recommendations for HR managers to cope with its deleterious consequences and for scholars to study them.     

Applying the counseling-learning approach to a tourism-related massive open online course

ABSTRACT

This study discusses how to apply counseling-learning (CL) principles to a particular e-learning solution for teaching a tourism-related subject via a massive open online course (MOOC). Several effective caring patterns in achieving learning-related goals and being part of a community according to the CL principles are presented and discussed using the MOOC “eTourism: Communication Perspectives” as a case study. The study underlines how the MOOC platform can act as a place for contents enjoinment and active learning. Moreover, the active role of social media for increasing the engagement of learners in the proposed activities and for developing a sense of the community is identified. In particular, Facebook and Twitter can act as places for community building and informal social interactions among learners that last beyond the completion of the course, which in turn can be a valid aid for continuing the relationships among instructors/learners and learners/learners, and for reaching new ones.     

MOOCs in tourism and hospitality: a review

ABSTRACT

Massive Open Online Courses (MOOCs) have grown significantly and globally in less than ten years. However, practices and research in tourism and hospitality MOOCs remain nascent. This study proposes the MOOC Components Framework with six groups of course components: scaffolding, lectures, networking, collaboration, assessment, and affirmation. Drawing on this framework and a case study method, the study analyses 18 tourism and hospitality MOOCs from higher education institutions. The results highlight that: tourism and hospitality MOOC offerings lack diversity; the forum is the preferred communication tool; social media are comparatively underused; the discontinuity of MOOC instructors needs attention; and finally, littless multilingual support is available.