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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
Αποτίμηση και πρόβλεψη περιουσιακών στοιχείων με χρονικά μεταβαλλόμενους συντελεστές βήτα.
No full textΗ βιβλιοθήκη διαθέτει αντίτυπο της διατριβής σε έντυπη μορφή.Διατριβή (Διδακτορική)--Πανεπιστήμιο Μακεδονίας, Θεσσαλονίκη, 2015.Περιλαμβάνει βιβλιογραφικές αναφορές (σ. 159-175).015/2015The theory of asset pricing relies heavily on the principles of present value calculations and the hypothesis of efficient capital markets. The former implies that the price of an asset, not necessarily stock, is a function of the expected future yields discounted to the current data. However, in the field of investments, there seems to be an important but unanswered question. This particular question is concerned with why some assets earn substantially higher average returns. Financial economists have developed different models to address this question in the context of theoretically or empirically motivated asset pricing models. The CAPM is considered to be the most widely used asset pricing model. However, in view of its empirical shortcomings, researchers have made many attempts to refine the theoretical foundations and improve its empirical performance. One of the main assumptions of the CAPM is the stability of beta coefficients. Because this assumption does not hold in reality, in this thesis we develop a novel approach for capturing the time variation of betas by treating the pattern as a function of market return. To do so, we construct a new two-factor model (TFM) which incorporates variables targeting to absorb the information conveyed by betas’ instability. The model is free from subjective bias problems related to the selection of a critical threshold. In addition, the important implications of predicting betas motivated us to examine empirically the accuracy of our TFM’s betas. Our analysis uses stocks traded on S&P 500 and covers a long period of time and different kinds of portfolios. The tests for finding out the model’s performance along with other well-known models proposed in the literature indicate that this novel approach is very promising. In addition, in this thesis we examine the existence of herding behaviour in different financial markets. Herding behaviour can have significantly consequences on the market efficiency, since it might aggravate volatility of returns destabilizing financial markets. Furthermore, nonlinearities of stock prices have been attributed to the existence of herding. Hence, in order to obtain a better understanding of herding, we examine its effects on market volatility. Furthermore, we seek for the existence of herding in factors other than the market risk such as co-skewness and co-kurtosis. Finally, we explore the existence of contagion effects of herding as well as if the measure of herding is affected by various unexpected macroeconomic shocks. We believe that the empirical findings reported in this thesis will help market participants and investors in many ways.Η θεωρία της αποτίμησης των περιουσιακών στοιχείων βασίζεται σε μεγάλο βαθμό στις αρχές του υπολογισμού της παρούσας αξίας και της υπόθεσης των αποτελεσματικών αγορών. Το πρώτο σημαίνει ότι η τιμή ενός περιουσιακού στοιχείου, όχι απαραίτητα μετοχής, είναι συνάρτηση των αναμενόμενων μελλοντικών αποδόσεων προεξοφλημένων στα τρέχοντα δεδομένα. Ωστόσο, στον τομέα των επενδύσεων, φαίνεται να υπάρχει ένα σημαντικό αλλά αναπάντητο ερώτημα. Το συγκεκριμένο ερώτημα έχει να κάνει με το γιατί ορισμένα περιουσιακά στοιχεία κερδίζουν σημαντικά υψηλότερες μέσες αποδόσεις. Οικονομολόγοι στον τομέα των χρηματοοικονομικών έχουν αναπτύξει διαφορετικά μοντέλα για να αντιμετωπίσουν αυτό το ζήτημα στο πλαίσιο των θεωρητικών ή εμπειρικών μοντέλων αποτίμησης. Το CAPM θεωρείται ότι είναι το πιο ευρέως χρησιμοποιούμενο μοντέλο αποτίμησης. Ωστόσο, υπό το φως των εμπειρικών μειονεκτημάτων του μοντέλου, οι ερευνητές έχουν κάνει πολλές προσπάθειες για τη βελτίωση του θεωρητικού υπόβαθρου του μοντέλου και της εμπειρικής του επίδοσης. Μία από τις βασικές παραδοχές του CAPM είναι η σταθερότητα των συντελεστών βήτα. Επειδή η υπόθεση αυτή δεν ισχύει στην πραγματικότητα, στην παρούσα διατριβή αναπτύσσουμε μια νέα προσέγγιση που εκτιμά τους χρονικά μεταβαλλόμενους συντελεστές βήτα ως συνάρτηση των αποδόσεων της αγοράς. Για να γίνει αυτό, έχουμε κατασκευάσει ένα νέο μοντέλο δύο παραγόντων (TFM), το οποίο ενσωματώνει μεταβλητές με σκοπό να απορροφήσει τις πληροφορίες που μεταφέρονται από την αστάθεια των συντελεστών βήτα. Το μοντέλο είναι απαλλαγμένο από προβλήματα υποκειμενικής μεροληψίας που σχετίζονται με την επιλογή κάποιου κρίσιμου ορίου. Επιπλέον, οι σημαντικές επιπτώσεις από την ακριβή πρόβλεψη των συντελεστών βήτα, μας δίνει το κίνητρο ώστε να εξετάσουμε εμπειρικά την ακρίβεια των συντελεστών βήτα του μοντέλου μας. Η ανάλυσή μας χρησιμοποιεί μετοχές που διαπραγματεύονται στο δείκτη S&P 500 και καλύπτει ένα μεγάλο χρονικό διάστημα και διάφορα είδη χαρτοφυλακίων. Οι εμπειρικοί έλεγχοι με άλλα γνωστά υποδείγματα της διεθνούς βιβλιογραφίας δείχνουν ότι η νέα αυτή προσέγγιση είναι πολύ ελπιδοφόρα. Επιπλέον, σε αυτή την εργασία εξετάζουμε την ύπαρξη της αγελαίας συμπεριφοράς των επενδυτών σε διάφορες χρηματοπιστωτικές αγορές. Η συγκεκριμένη συμπεριφορά μπορεί να έχει σημαντικές επιπτώσεις στην αποτελεσματικότητα της αγοράς, δεδομένου ότι θα μπορούσε να επιδεινώσει τη μεταβλητότητα των αποδόσεων και να οδηγήσει σε αποσταθεροποίηση των αγορών. Επιπλέον, η μη γραμμικότητα των τιμών των μετοχών έχει αποδοθεί στην ύπαρξη της αγελαίας συμπεριφοράς. Ως εκ τούτου, προκειμένου να κατανοήσουμε καλύτερα την αγελαία συμπεριφορά, εξετάζουμε τις επιπτώσεις της στη μεταβλητότητα των αγορών. Επιπλέον, εξετάζουμε την ύπαρξη της αγελαίας συμπεριφοράς και σε άλλους παράγοντες εκτός από τον κίνδυνο της αγοράς, όπως είναι η ασυμμετρία και η κύρτωση. Τέλος, διερευνούμε τις αλυσιδωτές επιπτώσεις της αγελαίας συμπεριφοράς καθώς επίσης και αν η τελευταία επηρεάζεται από διάφορα μακροοικονομικά σοκ. Πιστεύουμε ότι τα εμπειρικά αποτελέσματα που αναφέρονται στη συγκεκριμένη διατριβή, θα βοηθήσουν τους συμμετέχοντες στην αγορά και τους επενδυτές με πολλούς τρόπους
Are candidate countries converging with the EU in terms of the Copenhagen political criteria?
No full textThe Copenhagen criteria for EU accession are the essential preconditions that candidate countries must satisfy to be deemed eligible for membership. In line with the strand of the literature that focuses on candidate countries’ convergence with the EU, the paper examines whether converge with the EU in terms of the Copenhagen political criteria can be established empirically for candidate and potential-candidate countries. Currently, the candidate country status is granted to Albania, North Macedonia, Montenegro, Serbia and Turkey. Bosnia-Herzegovina and Kosovo are recognised by the EU as potential candidate countries. In addition to the candidate and potential candidate countries, we include in the convergence tests the six countries of the Eastern Partnership EU policy: Armenia, Azerbaijan, Belarus, Georgia, Moldova, Ukraine. Using unit root tests, convergence is examined in terms of two indices drawn from the Varieties of Democracy (V-Dem) project: the Liberal democracy and the Civil liberties indices. The findings reported herein, are not uniform and on the whole offer only scant evidence in favour of the convergence hypothesis. For some of the candidate and potential candidate countries convergence is established, while for others the results do not point to such a process.23563965
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Institutional quality convergence in the Euro area countries: a note and further evidence
No full textIn a recent paper in this journal, Pérez-Moreno et al. (2020) examine the presence of convergence or divergence in terms of institutional quality among the Eurozone countries over the period 2008-17. Convergence is a long-term process. Furthermore, it may not follow a smooth and stable course since it can be affected by major episodes such as the recent crisis and the recession that afflicted Eurozone countries. Better insights can be drawn with the use of timeseries spanning over a longer period and by allowing for structural shifts in the process caused by important episodes and major events.30465666
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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