This thesis fills a gap in the risk management literature and expands the understanding of the portfolio value at risk (VaR) by providing a theoretical market risk measurement of a portfolio (called “GEV-DCC model”), which combines the tail dynamic conditional correlation (tail-DCC) and extreme value theory. According to the spirit of VaR, the tail distribution is more important than the entire distribution, as well as the correlation in the tail area between various assets. The main advantage of this approach is the increase of accuracy in the parameter estimation of the tail distribution and more consistent correlation measurement for VaR. The results from this method are compared with four other conventional VaR approaches; GARCH model, RiskMetrics, stochastic volatility, and historical simulation. Furthermore, three quality measures are applied to evaluate the suitability, conservativeness, and magnitude of loss of the forecasted VaR, which offer more information from the forecasted VaR pattern. Applying 16 major equity index returns from developed and emerging markets, this study finds that the GEV-DCC model offers a more accurate coverage across the blocks in the three hypothetical portfolios (the developed equity markets, Asian and Latin American equity markets) compared with the four competing models. The uncovered rates of the GEV-DCC model with the 5-day block approach are generally close to the given probability (α) set in the VaR calculation. These consistent results can also be found in the robustness test with the shorter forecasting period. In the quality checks, the GEV-DCC presents a relatively stable pattern in the daily and 10-day VaR results. In addition, the GEV-DCC model also provides satisfactory results in the conservativeness and potential loss tests although no direct evidence indicates that it delivers the best result in these two checks. We also find significant differences between the original DCC and the tail-DCC. This evidence shows that the correlations between equity markets in the left tail are significantly higher than the ones in the right tail, and there are significant changes (generally rising) in the tail-DCC patterns around the period of financial crisis in the third quarter of 2008. The results from this study could potentially provide a critical reference for investors in measuring or managing the market risk.

As a result of an increasingly stringent regulation aimed at monitoring financial risk exposures, nowadays the risk measurement systems play a crucial role in all banks. In this thesis we tackle a variety of problems, related to density forecasting, which are fundamental to market risk managers. The computation of risk measures (e.g. Value-at-Risk) for any portfolio of financial assets requires the generation of density forecasts for the driving risk factors. Appropriate testing procedures must then be identified for an accurate appraisal of these forecasts. We start our research by assessing whether option-implied densities, which constitute the most obvious forecasts of the distribution of the underlying asset at expiry, do actually represent unbiased forecasts. We first extract densities from options on currency and equity index futures, by means of both traditional and original specifications. We then appraise them, via rigorous density forecast evaluation tools, and we find evidence of the presence of biases. In the second part of the thesis, we focus on modelling the dynamics of the volatility curve, in order to measure the vega risk exposure for various delta-hedged option portfolios. We propose to use a linear Kalman filter approach, which gives more precise forecasts of the vega risk exposure than alternative, well-established models. In the third part, we derive a continuous time model for the dynamics of equity index returns from a data set of 5-minute returns. A model inferred from high-frequency typical of risk measures calculations. The last part of our work deals with evaluating density forecasts of the joint distribution of the risk factors. We find that, given certain specifications for the multivariate density forecast, a goodness-of-fit procedure based on the Empirical Characteristic Function displays good statistical properties in detecting misspecifications of different nature in the forecasts.

Το φαινόμενο της χειραγώγησης των κερδών (earnings management) έχει απασχολήσει έντονα τα τελευταία χρόνια τις ρυθμιστικές αρχές, επενδυτές και γενικότερα τους χρήστες των εταιρικών οικονομικών καταστάσεων παγκοσμίως. Η παρούσα διατριβή σκοπό έχει τη διερεύνηση του βαθμού στον οποίο οι Ελληνικές επιχειρήσεις χειραγωγούν τα κέρδη τους με αποτέλεσμα άλλοτε να εμφανίζονται λιγότερα και άλλοτε περισσότερα από ότι στην πραγματικότητα είναι. Μέσω εφαρμογής διαφορετικών μελετών περιπτώσεων (case studies) και με τη χρησιμοποίηση νέων οικονομετρικών προσεγγίσεων για τον έλεγχο υποθέσεων τα συμπεράσματα συντείνουν στο ότι υψηλό ποσοστό ελληνικών επιχειρήσεων όντως χειραγωγούν τα κέρδη τους προκειμένου για την εξυπηρέτηση συγκεκριμένων στόχων. Πιο ενδιαφέρον δε είναι το συμπέρασμα ότι εφόσον υπάρχουν κίνητρα δεν διστάζουν να προβούν σε χειραγώγηση και άλλων λογιστικών μεγεθών όπως είναι οι πωλήσεις. / Earnings management has drawn increasing attention of regulators, accounting standard setters, and investors. The aim of this thesis is to investigate the extent of earnings management in the Greek context. By relying on superior econometric methodologies, applied in several different case studies, the conclusions confirm our hypotheses that a great percentage of Greek companies do manipulate their earnings in order to beat specific targets. More importantly, for a first time, it is provided empirical evidence that these companies, under certain circumstances, tend to manipulate other accounting variables as well i.e their reported sales.

Η πολιτική μερισμάτων απασχολεί τα Διοικητικά Συμβούλια όλων των επιχειρήσεων και λαμβάνεται υπόψη προκειμένου κάθε επιχειρηματική οντότητα να λάβει ορθές αποφάσεις για τη μελλοντική πορεία της. Στο πρώτο μέρος της εργασίας γίνεται μια εισαγωγή στο θέμα. Αναφέρονται οι στόχοι κάθε επιχείρησης, η έννοια του καθαρού κέρδους, ο ορισμός, οι τύποι και οι λειτουργίες των μερισμάτων, η έννοια της μερισματικής πολιτικής, τα είδη της και οι παράγοντες που την επηρεάζουν. Στο δεύτερο μέρος περιγράφεται ο αντικειμενικός σκοπός αυτής της εργασίας. Εν συνεχεία, στο τρίτο μέρος ακολουθεί μια σύντομη ιστορική αναδρομή, όπου γίνεται αναφορά των πιο σημαντικών μελετών κι ερευνών που έχουν διαδραματίσει σημαντικό ρόλο στη διατύπωση διαφόρων θεωριών περί μερισματικής πολιτικής. Στο τέταρτο μέρος επιχειρείται μια εμπειρική μελέτη επιχειρήσεων εισηγμένων στο Χρηματιστήριο της Νέας Υόρκης (New York Stock Exchange) έτσι ώστε να ερευνηθεί η σχέση των μερισμάτων τους με άλλα σημαντικά οικονομικά μεγέθη των εταιριών αυτών. Στο πέμπτο μέρος παρουσιάζονται τα εμπειρικά αποτελέσματα που προέκυψαν έπειτα από την εφαρμογή τριών διαφορετικών υποδειγμάτων καθώς επίσης και κάποια περιγραφικά στοιχεία. Στο έκτο και τελευταίο μέρος της διπλωματικής εργασίας αναφέρονται τα συμπεράσματα που διεξάγονται από τη μελέτη / The dividend policy employs the Boards of all businesses and taken into account in any business entity to take good decisions about their future course. In the first part of this work is an introduction to the subject. Describe the objectives of each company, the concept of profit, the definition, types and functions of dividends, the effect of dividend policy, types and factors affecting it. The second part describes the objective of this work. Subsequently, the third part follows a brief history, citing the most important studies and research have played an important role in formulating various theories on dividend policy. The fourth part attempts an empirical study of companies listed on the NYSE (New York Stock Exchange) to investigate the relationship between dividends with other key financial figures of those companies. The fifth part presents the empirical results obtained after applying three different models as well as some descriptive information. The sixth and final part of this thesis, the conclusions of the study conducted.

Στην παρούσα εργασία περιλαμβάνονται: η θεωρητική προσέγγιση του εσωτερικού ελέγχου (internal audit) στην οποία αναλύονται ο ορισμός του εσωτερικού ελέγχου και το πλαίσιο επαγγελματικής εφαρμογής. Τα ελεγκτικά πρότυπα και οι κανόνες συμπεριφοράς. Επίσης αναλύεται το σύστημα εσωτερικού ελέγχου και η επιτροπή ελέγχου, καθώς και η οργάνωση της διεύθυνσης εσωτερικού ελέγχου και η μεθοδολογία που ακολουθείται για τη διεξαγωγή των ελέγχων. Στο δεύτερο μέρος αναλύουμε το πλαίσιο διαχείρισης κινδύνων (Enterprise risk management) και περιγράφουμε πως διεξάγεται ο έλεγχος στις τράπεζες. Στο τρίτο μέρος παρουσιάζουμε ένα εξειδικευμένο πρόγραμμα ελέγχου σε κάποιο τραπεζικό ίδρυμα με επισυναπτόμενα φύλλα εργασίας και εργαλεία που χρησιμοποιούν οι ελεγκτές και τη μεθοδολογία κατάρτισης εκθέσεων εσωτερικού ελέγχου. Παραθέτουμε συμπεράσματα από την ανάλυση των πορισμάτων της διεύθυνσης εσωτερικού ελέγχου. Στο παράρτημα αναφέρουμε τα διεθνή πρότυπα εσωτερικού ελέγχου και παρουσιάζουμε υπόδειγμα φύλλου αυτοαξιολόγησης καταστήματος μιας τράπεζας. / Included in this work: a theoretical approach of internal audit explaining definition of internal audit and professional practice framework (PPF) and auditing standards and rules of conduct. We also analyzed the internal audit and audit committee, and the organization of internal audit and the methodology used for the audits. In the second part we analyse the risk management (enterprise risk management) and we describe how the audit is being conducted in the banks. In the third part we present in any bank foundation a specialized inspection program with attached work sheets and tools using the controllers and methods of preparation internal audit report. We set conclusions from the analysis of the findings of the internal audit manager. The annex lists international standards of internal audit and presents a model of self-assessment package for one bank.

Credit risk mitigation that can be applied by commercial banks in assessing the lending decision /credit risk when advances and equity investments are considered for BEE classified companies. / A research report presented to the Graduate School of Business Leadership, University of South Africa / The previous political dispensation limited black people’s participation in the South African economy. Poor credit records, lack of training, resulting in skills and capacity gaps further limited entry into the lending market. These aspects are considered the main limitations in obtaining finance for the Small, Medium and Micro Enterprises (SMMEs). This research report focuses on how credit risk can be mitigated by commercial banks in lending to Black Economic Empowerment (BEE) companies in the medium to large market. Exploratory research was conducted using various methods to achieve methodological triangulation. These methods consisted of a literature review, interviewing experts in the field and case studies. A qualitative research approach was followed. It was found that the lack of own contribution and security were still prevalent in the medium to large market, but the quality of management (little training and skills) was deemed not to be a limitation as suitable credit risk mitigants were identified. No credit risk mitigants were identified to mitigate poor credit records. It is postulated that by adopting and applying the identified credit risk mitigants, commercial banks can increase their success rate in lending to BEE companies. It will further assist in the transformation of black people and compliance with the Financial Services Charter. It is recommended that a similar study be conducted in the agriculture, hunting, forestry and fishing industry. The reasons why BEE companies applications are declined could also be investigated. Further studies could also explore other external factors such as economical, legal and social that could have an influence on the funding of BEE companies.

The research question and phenomenon that is addressed by this research study is: “What is the perceived importance and level of acceptance of ERM in the South African business environment, and what is the perceived value of ERM in South African organisations?” The definition of ERM utilised throughout this research study is: “Enterprise Risk Management is a process, effected by an entity’s board of directors, management and other personnel, applied in strategy setting and across the enterprise, designed to identify potential events that may affect the entity, and manage risk to be within its risk appetite, to provide reasonable assurance regarding the achievement of business objectives”. (Committee of Sponsoring Organisations of the Treadway Commission – COSO, 2004: 4) Enterprise Risk Management is perceived by many as being a necessity, but a burden to business caused by increased investor confidence requirements, such as adherence to King II, Basel II, JSE listing requirements, and the Public Finance Management Act in South Africa, and Sarbanes Oxley requirements placed on organisations listed in the USA, resulting primarily from recent international corporate failures. This causes ERM to be implemented for compliance reasons without obtaining the true value that ERM provides. The main research problem is therefore to firstly identify the extent of acceptance and implementation of ERM in organisations in the South African business environment, secondly identify the reasons why organisations implement ERM in these organisations, and thirdly identify factors that describe the perceived value that ERM provides to these organisations. / Graduate School of Business Leadership / MBL

The research question and phenomenon that is addressed by this research study is: “What is the perceived importance and level of acceptance of ERM in the South African business environment, and what is the perceived value of ERM in South African organisations?” The definition of ERM utilised throughout this research study is: “Enterprise Risk Management is a process, effected by an entity’s board of directors, management and other personnel, applied in strategy setting and across the enterprise, designed to identify potential events that may affect the entity, and manage risk to be within its risk appetite, to provide reasonable assurance regarding the achievement of business objectives”. (Committee of Sponsoring Organisations of the Treadway Commission – COSO, 2004: 4) Enterprise Risk Management is perceived by many as being a necessity, but a burden to business caused by increased investor confidence requirements, such as adherence to King II, Basel II, JSE listing requirements, and the Public Finance Management Act in South Africa, and Sarbanes Oxley requirements placed on organisations listed in the USA, resulting primarily from recent international corporate failures. This causes ERM to be implemented for compliance reasons without obtaining the true value that ERM provides. The main research problem is therefore to firstly identify the extent of acceptance and implementation of ERM in organisations in the South African business environment, secondly identify the reasons why organisations implement ERM in these organisations, and thirdly identify factors that describe the perceived value that ERM provides to these organisations. / Graduate School of Business Leadership / MBL

Στην εργασία αυτή προσεγγίζεται μια μέθοδος ιδιαίτερα γνωστή στον χρηματοπιστωτικό τομέα, με την οποία γίνεται αποτίμηση της αξίας σε κίνδυνο, Value at Risk, που είναι εκτεθειμένες μετοχές και χαρτοφυλάκιο, σύμφωνα με την συσχέτιση των αποδόσεων των περουσιακών τους στοιχείων, αλλά και το συστηματικό κίνδυνο αυτών σε σχέση με τις γενικές τάσεις της αγοράς. Χρησιμοποιώντας τις αποδόσεις 3 μετοχών, αλλά και ενός χαρτοφυλακίου μετοχών απο το Χρηματιστήριο Αξιών Αθηνών, ο βασικός στόχος της παρούσας διατριβής είναι να γίνει μια συγκρτική ανάλυση της αξίας σε κίνδυνο (VaR) για έναν επενδυτή με θέση αγοράς σε διάφορα επίπεδα εμπιστοσύνης και για δύο υποδείγματα δεσμευμένης ετεροσκεδαστικότητας (GARCH και E-GARCH). Για αυτή την συγκριτική ανάλυση, χρησιμοποιείται μια μεθοδολογία για τον έλεγχο των αποτελεσμάτων των παραπάνω υποδειγμάτων, γνωστή ως έλεγχος Kupiec. / In this Theses, we present an application well-known in the financial sector, Value at Risk, with which we measure the risk of stocks and portofolios. Using the returns of 3 stocks and a portofolio from the Greek Stock Exchange Market, the basic goal of the present theses is to make a comparative analysis of the value at risk for an investor with long rading position in various confidence levels and for two generalized autoregressive conditional heteroskedasticity models (GARCH and E-GARCH). For this comparative analysis, a methodology is used to backtest the results of the GARCH models, known as Kupiec Test.

Η παρούσα διπλωματική εργασία μελετά την επίδραση του κόστους περιστολής της ρύπανσης σε συγκεκριμένους κλάδους της ελληνικής βιομηχανίας, την χρονική περίοδο 1993-2006, στην παραγωγικότητά τους. Από θεωρητικής πλευράς εστιάζει στις αντικρουόμενες προσεγγίσεις της win-win υπόθεσης του Porter (1990,1991) και των Porter and Van der Linde (1995) με την νεοκλασική θεωρία, που είχε ως κύριους εκφραστές τους Jaffe και Palmer (1995,1997). Η μεθοδολογική προσέγγιση που ακολουθείται στηρίζεται στην μη παραμετρική μέθοδο της DEA με στόχο την εκτίμηση δεικτών παραγωγικότητας Malmquist (Malmquist Total Factor Productivity Index). Για την μελέτη της επίδρασης του κόστους περιστολής της ρύπανσης σε κλάδους της Ελληνικής βιομηχανίας ακολουθήθηκε η μεθοδολογία που αναπτύχθηκε απο τους Aiken et al., (2009) για τον διαχωρισμό και υπολογισμό μεταξύ regulated-unregulated συναρτήσεων ορίων παραγωγής. Στην εμπειρική εφαρμογή της μελέτης χρησιμοποιήθηκαν δεδομένα απο την ετήσια έρευνα βιομηχανίας της Ελληνικής Στατιστικής Υπηρεσίας σε 23 βιομηχανικούς κλάδους, σύμφωνα με την κωδικοποίηση ΣΤΑΚΟΔ 2003, και παρατηρείται συνολικά επουσιώδης αρνητική επίδραση τους κόστους περιστολής των ρύπων στην παραγωγικότητα. Πιο συγκεκριμένα, κλάδοι με υψηλή ενεργειακή ένταση φαίνεται να εμφανίζουν μηδενική επίδραση των περιβαλλοντικών δαπανών στην παραγωγικότητά τους με μοναδική εξαίρεση του κλάδου των ορυκτών-μετάλλων. / The passage of environmental regulation has been associated with a potential negative or positive effect on firm’s productivity. The present study studies the effect of pollution abatement activities on the productive efficiency of polluting industries in Greece over the period 1993-2006. A methodological approach based on Aiken et al., (2009) study have been developed in order to specify regulated and unregulated production frontiers and to determine the possible link between pollution abatement activities and sector’s productivity growth. Data derived form the Hellenic Statistical Authority has been used in order to estimate the possible association. Our results indicate, for the majority of the manufacturing industries, that increased rates of productivity growth have been simultaneously experienced with decreased rates of pollution abatement.