1,721,011 research outputs found
La regolamentazione dei servizi infrastrutturali
No full textA study of the issues relating to the regulation of aviation -- airport and air traffic -- infrastructure. Several specific issues are addressed: with regard to airports, slot management and regulation of charges; with regard to traffic control, regulation of charges and European funding of new investment. The main conclusions reached are that: slot management should not rely exclusively on the secondary trading of slots, but should also contemplate direct re-allocation of slots; charges levied at (large) airports should be regulated, as competition among airports is unlikely to impart an adequate market discipline; air traffic services should be subjected to incentive regulation, thus abandoning the common current practice of allowing full cost recovery; European funding of new investment in air traffic infrastructure should be considered, given that its features of an international public good are likely to result into distorted incentives and free riding problems. With regard to the Italian situation, it is maintained that reform of regulation should be accompanied by the establishment of a new, independent and specialized, regulatory body
A dissimilarity-based splitting criterion for CUBREMOT
No full textCUBREMOT (CUB REgression MOdel Trees) is a model-based approach to grow trees for ordinal responses that relies on a class of mixture models for evaluations and preferences (CUB). The original proposal considers deviances in loglikelihood to partition observations. In the present paper a new splitting criterion is introduced that, among the significant splitting variables, chooses the one that maximizes a dissimilarity measure. This choice is tailored to generating child nodes as far apart as possible with respect to the estimated probability distributions. An application to real data on Italians’ trust towards the European Parliament taken from the official survey on daily life conducted by the Italian National Institute of Statistics (ISTAT) in 2015 is presented and discussed in comparison with alternative methods
A Test for Variable Importance
No full textStatistical literature is being more and more concerned with debates about hypothesis testing and p-values supporting the significance of a given variable specification. Specifically, if on one hand statistical foundations about significance are not arguable, scholars should be able to distinguish between significance and variable importance. This is a matter of serious concern in questionnaire analysis to derive respondents’ profiles and develop targeted marketing strategies, for instance. To this aim, this contribution proposes a hypothesis system that considers the normalized dissimilarity measure to assess the importance of explanatory variables in the setting of mixture models for ordinal data to account for uncertainty of choice
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Valore del capitale e regolamentazione incentivante: una nota
No full textThe assessment of the value of capital performs an essential function in incentive regulation; at the same time, it involves considerable uncertainties and intricacies. The article discusses the three main available alternatives, i.e. historical (accounting) value, market value, and substitution value. A preference is expressed in favour of the last alternative -- as the alternative which embodies a concept of capital in line with the economic logic of regulation, and is also largely isolated by the problem of circularity between value of capital and level of profitability
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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