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.     

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.     

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.     

Organizing for continuous technology acquisition: the role of R&D geographic dispersion

External technology acquisition has been proved to be an important strategy to enhance firms’ innovation performance. However, previous studies claim that companies acquiring technologies tend to not carry on with this strategy over time, thus limiting their attitude toward continuous technology acquisition. Moreover, the extant literature also highlights that this attitude is strongly influenced by their organizational structure. Therefore, in the present paper, we investigate the relationship between how firms organize R&D activities and continuous technology acquisition. Specifically, given the increasing globalization of technological development, we focus on the role of R&D geographic dispersion, and how its influence is moderated by firms’ technological diversification. We tested our hypotheses on longitudinal data of 303 biotechnology firms that acquired, at least, one USPTO patented technology over the period 1982–2012. Results reveal that R&D geographic dispersion is curvilinearly (inverted U-shaped) related to continuous technology acquisition, with negative returns occurring earlier in technology-diversified companies.     

Inter‐firm R&D collaborations and green innovation value: The role of family firms' involvement and the moderating effects of proximity dimensions

The present paper investigates the relationship between the involvement of family firms in R&D collaborations aimed at developing green solutions and the value of resulting innovations. To dig into this relationship, the moderating effects of two proximity dimensions (i.e., geographical distance and technological relatedness) are also assessed. Analyses are based on a sample of 156 joint patents classified into the “Alternative energy production” field, as defined by the International Patent Classification Green Inventory and successfully filed at the United States Patent and Trademark Office in the period 1997–2010 by publicly listed companies. According to our conjectures, results reveal a positive relationship between the involvement of family firms and green innovation value. Moreover, our findings show that this relationship is hindered when partners are geographically distant or technologically proximate. Eventually, we contribute to the literature on green innovation by unveiling under which conditions inter‐firm R&D collaborations lead to more valuable innovations.     

Micro versus macro cointegration in heterogeneous panels

We consider the issue of cross-sectional aggregation in nonstationary and heterogeneous panels where each unit cointegrates. We derive asymptotic properties of the aggregate estimate, and necessary and sufficient conditions for cointegration to hold in the aggregate relationship. We then analyze the case when cointegration does not carry through the aggregation process, and we investigate whether the violation of the formal conditions for perfect aggregation can still lead to an aggregate equation that is observationally equivalent to a cointegrated relationship. We derive a measure of the degree of noncointegration of the aggregate relationship and we explore its asymptotic properties. We propose a valid bootstrap approximation of the test. A Monte Carlo exercise evaluates size and power properties of the bootstrap test.     

THE PREDICTABILITY OF AGGREGATE CONSUMPTION GROWTH IN OECD COUNTRIES: A PANEL DATA ANALYSIS

We examine aggregate consumption growth predictability. We derive a dynamic consumption equation which encompasses relevant predictability factors: habit formation, intertemporal substitution, current income consumption and non‐separabilities between private consumption and both hours worked and government consumption. We estimate this equation for a panel of 15 OECD countries over the period 1972–2007, taking into account parameter heterogeneity, endogeneity and error cross‐sectional dependence using a GMM version of the common correlated effects mean group estimator. Small‐sample properties are demonstrated using Monte Carlo simulations. The estimation results support income growth as the only variable with significant predictive power for aggregate consumption growth. Copyright © 2013 John Wiley & Sons, Ltd.