Τμήμα Οικονομικών Επιστημών (ΔΔ)

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Essays on the macroeconomic effects of reforms
(2026-05-19) Μαυρόγιαννης, Χρήστος; Mavrogiannis, Christos
This thesis, entitled “Essays on the Macroeconomic Effects of Reforms,” consists of three chapters that examine the macroeconomic effects of structural reforms and the conditions under which they are most effective. It focuses on the effects of reforms on output, capital inflows, and private investment, while emphasising the role of institutional quality and policy environment in shaping these outcomes. The first chapter investigates the impact of real and financial reforms on economic growth. The analysis shows that structural reforms have a positive effect on output in the medium to long run. It further highlights the importance of institutional quality, demonstrating that reforms are more effective in countries with stronger governance, higher regulatory quality, and a well-established rule of law. The second chapter examines the effects of product and labor market reforms on gross capital inflows. The findings indicate that reforms may have short-term neutral or negative effects on foreign direct investment and portfolio investment, but generate positive and significant gains over the medium term. The chapter also shows that the effectiveness of reforms depends on macroeconomic conditions, such as public debt levels, and on the policy orientation of governments. In particular, shifts toward more market-oriented policies are associated with higher capital inflows, while the interaction between reforms and political orientation plays a key role in shaping investment responses. The third chapter explores the effects of structural reforms on private investment. The results suggest that both product and labor market reforms stimulate private investment in the long run, with labor market reforms having a stronger impact. The analysis further demonstrates that institutional quality and financial development are critical in amplifying these effects, as reforms are more effective in environments characterized by strong legal frameworks and deeper financial systems.
Open Access
Essays on efficiency and strategy of innovation focusing on heterogeneity and eco-innovation
(2025-10-29) Κουτσουράδης, Γεώργιος; Koutsouradis, George
1. Thesis Focus and Structure The central focus of this dissertation is the investigation of the relationship between, on one side, the heterogeneity of firms’ innovation strategies and, on the other, the returns on their investments in innovative activities, with particular emphasis on environmental innovations. Returns are defined both in terms of technological innovation frontiers, using efficiency metrics, and in terms of the contribution of innovative activities to the broader set of firm operations, using innovation performance metrics. The Dissertation is structured in six (6) chapters. The first chapter establishes the overall framework, identifying the broader research gaps in the international literature both in theory and methodology, and emphasises the importance of addressing these gaps. The second chapter presents the data utilised for the empirical analysis. Specifically, it outlines the framework of the Community Innovation Survey (CIS) conducted by Eurostat and focuses on aspects of innovation strategy, intellectual property rights (IPR), ambidexterity, and the survey modules related to environmental innovation. In this context, the significance of studying innovation strategy and environmental innovation in follower countries (also referred to as non-usual suspects), where innovation systems are fragmented, is established. Below, I briefly present the main points of the Dissertation, which are developed around the following pillars: • Innovation Strategy Efficiency and Strategic Complexity • Environmental Innovation and Firm Size: A Configurational Approach • Environmental Process Innovation and Complementary Strategic Assets 2. Innovation Strategy Efficiency and Strategic Complexity The first essay examines the structural trade-off between innovation efficiency and the complexity of innovation strategy. Drawing on Teece’s (1986; 2018) Profiting from Innovation (PFI) framework, the chapter develops an original theoretical and methodological approach that goes beyond standard treatments by endogenising strategic choices into the efficiency estimation process, taking into account the role of complementary assets. It links firms’ competitive positioning to the innovation strategies they adopt, identifying two latent groups of innovative firms: (i) firms pursuing short-term returns based on innovation efficiency (competitive rent seekers), and (ii) firms seeking medium- to long-term monopoly rents (monopoly rent seekers). Two dimensions of innovation strategy are analysed: the breadth of the IPR portfolio, and ambidexterity in product and process innovation. Efficiency is estimated relative to heterogeneous innovation frontiers. The analysis shows that strategic complexity has significant implications for efficiency. While broad IPR portfolios may provide protection, rents, and bargaining power, they also involve managerial costs and uncertainty that tend to reduce efficiency. By contrast, narrower IPR strategies that allow faster appropriation of innovation outputs are associated with higher efficiency. Moreover, pursuing both ambidexterity and broad IPR portfolios further burdens efficiency. This results in a hierarchical structure of innovation strategies, shaped by competitive positioning, and reflected in heterogeneous but ordered innovation frontiers. The contribution of this essay lies in bridging the literature on innovation efficiency with that on innovation strategy, offering a unified understanding of how strategic complexity shapes efficiency boundaries. Methodologically, it introduces a new type of Data Envelopment Analysis (DEA), the Innovation Strategy DEA (ISDEA), which allows the endogenous incorporation of strategic innovation choices. Managerially, the results suggest that firms must first recognise their competitive position and consider efficiency losses when adding layers of strategic complexity. At the policy level, the findings point to the need for more effective IPR regimes, particularly in contexts characterised by limited innovation capabilities, where complementary assets are scarce. 3. Environmental Innovation and Firm Size: A Configurational Approach This essay examines the relationship between environmental innovation and innovation performance using a configurational approach informed by complexity theory. Innovation performance is measured as the share of sales from new or significantly improved products. In contrast to traditional approaches that estimate net effects, the analysis shows that innovation performance results from multiple, simultaneous, and potentially alternative strategic configurations. The study considers environmental product and process innovations alongside access to external knowledge and internal absorptive capacity, reflecting firms’ knowledge base. Using fuzzy-set Qualitative Comparative Analysis (fsQCA), the results show that small, medium, and large firms follow distinct strategic configurations leading to high innovation performance. Small firms benefit from external innovation collaborations that compensate for limited internal capabilities. Medium-sized firms, with stronger internal knowledge bases, combine process-oriented environmental innovations with complementary strategic elements. Large firms leverage environmental product innovation, supported by R&D investments and systematic access to external knowledge networks. The contribution is twofold: theoretically, it advances the literature on environmental innovation by integrating complexity and equifinality, demonstrating that there is no single strategic path to high innovation performance. Empirically, it provides strategy roadmaps tailored to technological and organisational characteristics across firm-size classes, informing policy discussions on green competitiveness. 4. Environmental Process Innovation and Complementary Strategic Assets This essay examines the impact of environmental process innovation on innovation performance, with a focus on marketing innovation as a complementary asset. A distinction is drawn between End-of-Pipe Technologies (EPT), adopted under regulatory pressure to reduce externalities, and Resource-Efficient Technologies (RET), adopted to improve efficiency. A four-equation structural model is estimated, one equation correcting for selection bias in the adoption of environmental innovations, using Conditional Mixed Process estimators. Principal Components Analysis is used to classify environmental innovations into RET and EPT categories. The results show that RET are positively associated with innovation performance, supporting the “win–win” logic. In contrast, EPT tend to reduce innovation performance due to costs and complexity. However, marketing innovation can counterbalance or reverse the negative effects of EPT, enabling firms to commercialise compliance-driven innovations. This highlights marketing innovation as a strategic asset that transforms constraint into opportunity. The essay situates itself at the intersection of research on environmental innovation adoption and its effects on performance. It shows that firms compelled by external pressures rely on marketing capabilities to extract value from innovation, while internally-driven environmental strategies yield performance benefits even without marketing complementation. 5. Conclusions, Limitations, and Future Research The Dissertation contributes to the economics of innovation strategy by emphasising how strategic choices condition both the efficiency and performance of innovation investments, especially in environmental innovation contexts. It incorporates strategic factors—IPR breadth, ambidexterity, and distinctions between types of environmental technologies—into the measurement of innovation outcomes, and analyses configurational strategy patterns across firm sizes. Managerially, the findings suggest that decision-makers should weigh the costs and benefits of broad IPR portfolios and simultaneous product–process innovation. In environmental innovation, strategies should differ by firm size and knowledge base. The choice between RET and EPT carries distinct implications, and marketing innovation is particularly important when dealing with EPT. At the policy level, the results support the design of differentiated innovation policies based on firm heterogeneity, simplification of the IPR framework in the EU, strengthening of collaboration mechanisms for SMEs, and the development of differentiated policy instruments for RET and EPT. The dissertation is subject to certain limitations. The use of cross-sectional data limits the ability to identify causal relationships, instead focusing on associations. To strengthen causal inference and examine the temporal evolution of environmental innovation strategies, future research would benefit from drawing on panel data, which are currently not available. In addition, the study focuses on countries with moderate innovation performance, leaving open the question of whether the findings can be applied to more advanced innovation ecosystems. Finally, exploring other potential complementary assets such as R&D collaborations, organisational innovations, and business model innovations would be particularly insightful. Overall, the possible synergies form a broad yet promising field for further investigation.
Open Access
Η διεθνοποίηση των πανεπιστημίων με βάση τη γεωγραφική τους θέση
(2025-04-01) Γεωργουδάκη, Ελένη; Georgoudaki, Eleni
Η διατριβή διερευνά τις διαδρομές μέσα από τις οποίες η διεθνοποίηση των πανεπιστημίων επηρεάζεται και επηρεάζει τη γεωγραφική τους θέση. Κεντρικό θεωρητικό στοιχείο και έναυσμα αποτελεί η αυξανόμενη σημασία της διεθνοποίησης ως στρατηγικής προτεραιότητας για τα πανεπιστήμια, προσφέροντας οφέλη όπως η ενισχυμένη κινητικότητα των φοιτητών, των φοιτητριών καθώς και το κύρος του ιδρύματος. Η διατριβή περιορίζεται στο πρόγραμμα Erasmus, που, όμως, αποτελεί το βασικό εργαλείο για τη κινητικότητα των φοιτητών και των φοιτητριών στην Ευρώπη. Οι κύριοι στόχοι της εργασίας περιγράφονται σε δύο επίπεδα: στο μάκρο και στο μίκρο γεωγραφικό επίπεδο. Στο μάκρο επίπεδο η έρευνα περιλαμβάνει το σύνολο της Ευρωπαϊκής Ένωσης με σκοπό να μελετήσει τη γεωγραφία της εισερχόμενης κινητικότητας. Στο μίκρο επίπεδο απομονώνεται ένα πανεπιστήμιο, το Πανεπιστήμιο της Πάτρας, και η περιοχή του, που λειτουργεί ως μελέτη περίπτωσης για να εξαχθούν πιο λεπτομερή και ποιοτικά δεδομένα. Στην περίπτωση της συνολικής μάκρο θεώρησης, η ανάλυση έχει τρείς σκοπούς: • Να διερευνήσει τη γεωγραφία της εισερχόμενης κινητικότητας φοιτητών και φοιτητριών Erasmus (incoming Erasmus students) την περίοδο 2014-2020, που ουσιαστικά περιορίστηκε λόγω COVID-19 στην περίοδο 2014-2019. Ως γεωγραφία νοείται εδώ η χωρική κατανομή και ως εισερχόμενος φοιτητής, μέσω κινητικότητας, οι φοιτητές και οι φοιτήτριες των επιπέδων εκπαίδευσης ISCED 5 έως και 8 που γίνονται δεκτοί σε εκπαιδευτικά ιδρύματα, που συμμετέχουν στο πρόγραμμα Erasmus. Η χωρική κατανομή εξετάζεται στον απόλυτο αριθμό μετακινούμενων φοιτητών και φοιτητριών και στον λόγο μετακινούμενων προς συνολικό αριθμό φοιτητών των ιδρυμάτων. • Να ελέγξει εάν οι περιφερειακές συσσωματώσεις των δεδομένων των μετακινούμενων φοιτητών ευθύνονται για οποιοδήποτε σημαντικό μέρος της συνολικής διακύμανσης της κινητικότητας των φοιτητών του προγράμματος Erasmus στην Ευρώπη. • Να διερευνήσει εάν οι περιφερειακές μεταβλητές και οι μεταβλητές που αντανακλούν τα χαρακτηριστικά των Ιδρυμάτων Τριτοβάθμιας Εκπαίδευσης οι οποίες βρέθηκε να επηρεάζουν την προσέλκυση των φοιτητών της περιόδου 2007-2013, σύμφωνα με τη μελέτη του Joint Research Center της Ευρωπαϊκής Ένωσης (Barrioluengo και Flisi, 2017), συνεχίζουν να παραμένουν σημαντικοί παράγοντες και στην περίοδο 2014-2020 ή έχει επέλθει μια σημαντική στροφή στους παράγοντες που επηρεάζουν την κινητικότητα. Στην περίπτωση της μίκρο θεώρησης με τη μελέτη περίπτωσης του Πανεπιστημίου της Πάτρας, οι στόχοι και οι σκοποί της εργασίας περιλαμβάνουν την εξέταση των αλληλεπιδράσεων μεταξύ της πόλης της Πάτρας, του Πανεπιστημίου Πατρών και των ξένων φοιτητών και φοιτητριών του μέσω της χρήσης διαφόρων χαρτογραφικών εργαλείων. Συγκεκριμένα, η μελέτη προσπάθησε να διερευνήσει και να κατανοήσει: • Τον τρόπο με τον οποίο η πολιτιστική εικόνα της πόλης επηρεάζει τη στρατηγική διεθνοποίησης του πανεπιστημίου και παρακινεί τους διεθνείς φοιτητές να σπουδάσουν εκεί. • Τον τρόπου με τον οποίο οι διεθνείς φοιτητές και οι φοιτήτριες μπορούν να εμπλακούν στην πολιτιστική ανάδειξη της πόλης και να συμβάλουν στην αστική βελτίωση κατά τη διάρκεια της παραμονής τους. • Πώς, μέσα από χρήση εφαρμογών GIS, γνωστικής χαρτογράφησης και χαρτογραφημάτων, μπορούν να αποκαλυφθούν και να απεικονισθούν αλληλεπιδράσεις και αντιλήψεις των ξένων φοιτητών σχετικά με τις εμπειρίες τους στην Πάτρα. • Τα δυνατά και αδύναμα σημεία της ζωής των ξένων φοιτητών στην Πάτρα. • Την συμβολή στην ενίσχυση της στρατηγικής διεθνοποίησης του πανεπιστημίου και στη μεγιστοποίηση της ικανοποίησης των ξένων φοιτητών ως παράγοντες αστικής βελτίωσης. Η διατριβή χρησιμοποιεί πληθώρα μεθοδολογικών προσεγγίσεων με κυριότερες: Την ανάλυση Hot Spot: Μία χωρική στατιστική τεχνική που προσδιορίζει γεωγραφικές περιοχές, όπου οι παρατηρούμενες τιμές μιας μεταβλητής αποκλίνουν σημαντικά από τις αναμενόμενες τιμές, αποκαλύπτοντας συστάδες υψηλών (hot spots) ή χαμηλών (cold spots) τιμών σχετικά με τον αριθμό των εισερχόμενων φοιτητών Erasmus. Η ανάλυση χρησιμοποιεί εργαλεία όπως η στατιστική Getis-Ord Gi για την αξιολόγηση του βαθμού χωρικής ομαδοποίησης μεταξύ των Ιδρυμάτων Ανώτατης Εκπαίδευσης. Πολυεπίπεδη Ανάλυση: Μία στατιστική προσέγγιση που αναγνωρίζει την χωρική ιεραρχική δομή των δεδομένων (με τα Ιδρύματα συσσωματωμένα σε διοικητικές γεωγραφικές περιοχές) και επιτρέπει την εξέταση της διακύμανσης, τόσο σε επίπεδο Ιδρύματος όσο και σε περιφερειακό επίπεδο. Στη διατριβή χρησιμοποιείται ένα μοντέλο δύο επιπέδων για τη μέτρηση της διακύμανσης μεταξύ και εντός περιοχών και για τον εντοπισμό περιφερειακών και ιδρυματικών παραγόντων πρόβλεψης της κινητικότητας Erasmus. Στη μελέτη περίπτωσης οι κύριες μεθοδολογικές προσεγγίσεις που χρησιμοποιούνται περιλαμβάνουν: Εφαρμογές Συστημάτων Γεωγραφικών Πληροφοριών (GIS), που χρησιμοποιούνται για τη διερεύνηση της διανομής δια-ιδρυματικών συμφωνιών Erasmus και της κατανομής των εισερχόμενων φοιτητών και φοιτητριών Erasmus ανά Τμήμα στο Πανεπιστήμιο Πατρών κατά τη διάρκεια δύο περιόδων (2007–2013 και 2013–2018). Γνωστική χαρτογράφηση, όπου διεθνείς φοιτητές και φοιτήτριες Erasmus σχεδιάζουν χάρτες, για να απεικονίσουν τις αντιλήψεις τους για την πόλη της Πάτρας. Αυτοί οι χάρτες χρησιμεύουν ως μέσο για να ενθαρρύνουν την αποτύπωση των αντιλήψεων και να εκφράσουν σκέψεις σχετικά με τις εμπειρίες των φοιτητών και των φοιτητριών στο χώρο. Χαρτογράμματα, που αποτελούν την επεξεργασία των γνωστικών χαρτών που δημιουργούνται από τους διεθνείς φοιτητές και φοιτήτριες και τα οποία αναπαριστούν οπτικά ποιοτικά δεδομένα σε ένα χωρικό πλαίσιο. Αυτό επιτρέπει τον εντοπισμό των δυνατών και των αδύναμων σημείων στον πολεοδομικό σχεδιασμό της Πάτρας-πόλης υποδοχής, με βάση τις αντιλήψεις των φοιτητών. Μια ενδελεχής μελέτη της διεθνούς βιβλιογραφίας διέκρινε τους παράγοντες που επηρεάζουν τη διεθνή κινητικότητα φοιτητών και φοιτητριών σε τρία επίπεδα: ατομικό, ιδρυματικό και εθνικό – διεθνές. Με βάση τη βιβλιογραφία και την προσωπική εμπειρία μας θέσαμε τα ερευνητικά ερωτήματα που σχετίζονται με την επιρροή που ασκεί η γεωγραφική θέση μέσω της μελέτης συγκεκριμένων κοινωνικοοικονομικών και εκπαιδευτικών χαρακτηριστικών στην προσέλκυση εισερχόμενης κινητικότητας φοιτητών και φοιτητριών. Τα δεδομένα της μάκρο μελέτης αντλήθηκαν όλα από ανοιχτές βάσεις δεδομένων, ως εκ τούτου, είναι άμεσα και ελεύθερα προσπελάσιμα από οποιονδήποτε. Αυτό δίνει στην έρευνα την αμεσότητα της επαλήθευσης των μεθόδων, των αποτελεσμάτων και των συμπερασμάτων. Η κυριότερη βάση δεδομένων είναι ο κατάλογος της Ευρωπαϊκής Τριτοβάθμιας Εκπαίδευσης (European Tertiary Education Register – ETER) για τα συμμετέχοντα ιδρύματα και τα δεδομένα κινητικότητας. Η Eurostat είναι η βάση για τα περιφερειακά δεδομένα. Για την κατάταξη των ιδρυμάτων ως προς τη φήμη τους, χρησιμοποιούμε τη μεθοδολογία του πανεπιστημίου της Leiden 2024 και του Κέντρου Μελετών Επιστήμης και Τεχνολογίας (CWTS), η οποία βασίζεται σε βιβλιογραφικά δεδομένα από τη βάση δεδομένων Web of Science της Clarivate. Τα περιφερειακά δεδομένα αντλούνται από τη Eurostat, ειδικότερα από την ενότητα «Περιφερειακές στατιστικές κατά ταξινόμηση NUTS (reg)». Η γεωαναφορά των Ιδρυμάτων Ανώτατης Εκπαίδευσης (AEI) προήλθε από τη μελέτη του Gadár et al. (2020), ενώ τα διοικητικά όρια της Ευρωπαϊκής Ένωσης προέρχονται από το «Γεωγραφικό Σύστημα Πληροφοριών της Επιτροπής». Για την μάκρο ανάλυση, η στατιστική μονάδα ήταν τα συμμετέχοντα ιδρύματα στο πρόγραμμα Erasmus. Από τις παραπάνω βάσεις διαμορφώσαμε το δείγμα έρευνας, που είναι τα ανώτατα εκπαιδευτικά ιδρύματα που αναφέρουν δεδομένα στη βάση ETER, και μέσω της γεωαναφοράς τα ταξινομήσαμε σε διοικητικές περιφερειακές μονάδες NUTS2. Για τη μίκρο ανάλυση, η ποιοτική μονάδα μέτρησης είναι ο διεθνής φοιτητής και φοιτήτρια που συμμετείχε στην έρευνα στο πανεπιστήμιο της Πάτρας. Στο μακρο γεωγραφικό επίπεδο η μελέτη καταλήγει στο συμπέρασμα ότι το πρόγραμμα Erasmus+ επηρεάζει σημαντικά τη διεθνοποίηση των ιδρυμάτων τριτοβάθμιας εκπαίδευσης σε ολόκληρη την Ευρώπη, αποκαλύπτοντας χωρικές ανισότητες στην κινητικότητα των φοιτητών και των φοιτητριών. Χώρες όπως η Ισπανία, η Γερμανία και το Ηνωμένο Βασίλειο φιλοξενούν πολλούς φοιτητές Erasmus, ενώ στατιστικά σημαντικά hotspot εντοπίζονται κυρίως στην Ισπανία, την Πορτογαλία και περιοχές της νότιας Γαλλίας, με απροσδόκητα hotspots να εμφανίζονται στην Ιρλανδία και τη Σουηδία. Επιπλέον, η ανάλυση δείχνει περιορισμένη επικάλυψη μεταξύ του απόλυτου αριθμού εισερχόμενων φοιτητών και φοιτητριών και της αναλογίας των φοιτητών Erasmus προς το σύνολο του εγγεγραμμένου πληθυσμού, υποδηλώνοντας, ότι τα ιδρύματα που έχουν υψηλό σκορ στη μία μέτρηση μπορεί να μην έχουν απαραίτητα καλή απόδοση στην άλλη. Επιπλέον, τα ευρήματα του πολύ-επίπεδου υποδείγματος υπογραμμίζουν τη σημασία των περιφερειακών κοινωνικοοικονομικών χαρακτηριστικών για την προσέλκυση φοιτητών Erasmus και προτείνουν στοχευμένες πολιτικές για τη βελτίωση της ελκυστικότητας των λιγότερο δημοφιλών περιοχών. Η μίκρο θεώρηση καταλήγει στο συμπέρασμα ότι οι αλληλεπιδράσεις μεταξύ του Πανεπιστημίου Πατρών, της πόλης της Πάτρας και των διεθνών φοιτητών του μέσω προγράμματος ανταλλαγών, επηρεάζονται σημαντικά από το πολιτιστικό προφίλ της πόλης. Η εισαγωγή εξειδικευμένων μαθημάτων για την ελληνική γλώσσα και τον πολιτισμό οδήγησε σε αύξηση των εισερχομένων φοιτητών και φοιτητριών από διαφορετικούς επιστημονικούς τομείς, βελτιώνοντας την αλληλεπίδραση και ενασχόλησή τους με την πόλη. Επιπλέον, οι γνωστικοί χάρτες των φοιτητών υπογραμμίζουν τις αστικές αποτυχίες και παρέχουν πολύτιμες γνώσεις σε αυτούς που είναι επιφορτισμένοι με τον αστικό σχεδιασμό. Συνολικά, οι διεθνείς φοιτητές και φοιτήτριες διαδραματίζουν κρίσιμο ρόλο ως φορείς αστικής βελτίωσης, ενισχύοντας τόσο την προσωπική τους ανάπτυξη όσο και το πολιτιστικό περιβάλλον της Πάτρας.
Open Access
Επιχειρηματικά δίκτυα και καινοτομία : κείμενα μελέτης του αγροδιατροφικού συστήματος προϊόντων γεωγραφικής ένδειξης (ΠΟΠ κ ΠΓΕ)
(2025-04-02) Γούδη, Αλεξάνδρα; Goudis, Alexandra
Η πολιτική των γεωγραφικών ενδείξεων (ΓΕ) εφαρμόστηκε σε όλες τις ευρωπαϊκές περιφέρειες ως ένα "χωροταξικά τυφλό" μέσο ρυθμιστικής αγροτικής πολιτικής για τη βελτίωση της οικονομικής βιωσιμότητας των αγροτικών περιοχών και την διασφάλιση της ποιότητας της τοπικής παραγωγής. Από την αρχή της πολιτικής παρατηρήθηκε ανομοιομορφία στην υιοθέτησή της από τις ευρωπαϊκές περιφέρειες, αποκαλύπτοντας πολύπλοκα τοπικά, κοινωνικά και θεσμικά δίκτυα που επηρεάζουν την εφαρμογή της. Η παρούσα διατριβή αποτελείται από τρεις ξεχωριστές μελέτες και ερευνά την εξέλιξη της πολιτικής της Ευρωπαϊκής Ένωσης για τις γεωγραφικές ενδείξεις από το 1992 έως το 2024, εστιάζοντας στο ρόλο της ως καινοτόμου συστήματος για την οργάνωση της γεωργικής παραγωγής και την δημιουργία σύγχρονων επιχειρηματικών δικτύων. Το πρώτο μέρος της διδακτορικής διατριβής [κεφάλαιο 3] μελετά τη γεωγραφία της πρώιμης υιοθέτησης των ΓΕ, από το 2000 έως το 2008 και αποσκοπεί στη διερεύνηση του κατά πόσον συγκεκριμένες Ευρωπαϊκές περιφέρειες διέθεταν εγγενή πλεονεκτήματα που διευκόλυναν την αποτελεσματικότερη εφαρμογή της πολιτικής των ΓΕ. Επίσης, εξετάζει το ενδεχόμενο οι πρώτοι υιοθετητές (early adopters) να προσέδωσαν συγκριτικό πλεονέκτημα στις περιφέρειες ενισχύοντας τον αγροδιατροφικό τομέα τους. Η μελέτη διερευνά περαιτέρω τη σχέση μεταξύ των γεωγραφικών ενδείξεων και του σχηματισμού ισχυρών συστάδων στην αγροδιατροφική αλυσίδα, χρησιμοποιώντας την μεθοδολογία τριών παραγόντων χωρικής συγκέντρωσης (μέγεθος, εξειδίκευση, εστίαση) του Ευρωπαϊκού Παρατηρητηρίου Συστάδων. Κατά τη διάρκεια της περιόδου επέκτασης, από το 2008 έως το 2018, οι αυστηρότερες απαιτήσεις επισήμανσης αποσκοπούσαν στη βελτίωση της καταναλωτικής ενημέρωσης, αλλά η αναγνώριση των ετικετών ΓΕ παρέμεινε χαμηλή, εγείροντας προβληματισμό για τη θεμελιώδη και κυρίαρχη αιτιολόγηση αυτής της πολιτικής και ακυρώνοντας τις επιπτώσεις της τόσο στους καταναλωτές όσο και στους παραγωγούς. Το δεύτερο μέρος της διατριβής [κεφάλαιο 4] χαρτογραφεί τους καταναλωτές κατά τη διάρκεια αυτής της περιόδου και εξετάζει μεθόδους προσέγγισης των Ευρωπαίων καταναλωτών. Η σήμανση ποιοτικών τροφίμων και η εθελοντική ή υποχρεωτική χρήση λογότυπων, σε συνδυασμό με την εμφάνιση και την ανάπτυξη πολλών εναλλακτικών αλυσίδων εφοδιασμού τροφίμων, θα πρέπει να ανταποκρίνονται στις ανησυχίες των καταναλωτών για το περιβάλλον, την κλιματική αλλαγή και μια σειρά ηθικών ή πολιτικών ζητημάτων. Τα δεδομένα αντλήθηκαν από ένα δείγμα περίπου 110.000 ερωτηθέντων με τη συγκέντρωση τεσσάρων κυλιόμενων ερευνών του Ευρωβαρόμετρου από το 2012 έως το 2017. Κατά την πιο πρόσφατη περίοδο, από το 2018 έως και σήμερα, οι επιπτώσεις της κλιματικής αλλαγής επηρέασαν την παραγωγικότητα και την κερδοφορία του αγροτικού τομέα, δημιουργώντας νέες προκλήσεις για τη διασφάλιση της μακροπρόθεσμης βιωσιμότητας αυτών των γεωργικών συστημάτων. Το τρίτο μέρος της διατριβής [κεφάλαιο 5] εστιάζει στη μεσογειακή γεωργία, όπου η ταχεία θέρμανση της περιοχής θα μπορούσε να οδηγήσει σε μειωμένες αποδόσεις των καλλιεργειών, αυξημένη λειψυδρία και προκλήσεις για την επισιτιστική ασφάλεια. Εξετάζουμε την περίπτωση του Κρητικού προϊόντος ΠΟΠ «Θρούμπα Αμπαδιάς», όπου αποδεικνύεται η εξάρτησή της από τις τοπικές κλιματικές συνθήκες, καταγράφονται τα προληπτικά μέτρα για τη διασφάλιση της μακροπρόθεσμης βιωσιμότητας αυτών των γεωργικών συστημάτων και τονίζεται η ανάγκη για στρατηγικές προσαρμογής διατηρώντας παράλληλα την τοπική πολιτιστική κληρονομιά που σχετίζεται με αυτά τα προϊόντα. Οι πληροφορίες για την «Θρούμπα Αμπαδιάς» αντλήθηκαν από την βάση δεδομένων Γεωγραφικών Ενδείξεων e-ambrosia και οι μελλοντικές κλιματικές προβολές βασίστηκαν σε 2 από τα 3 σενάρια εκπομπών αερίων του θερμοκηπίου (Representative Concentration Pathways) της IPCC. Συγκεκριμένα, τα κλιματικά δεδομένα έχουν παραχθεί για 2 μελλοντικές περιόδους 2031-2060 και 2071-2100 με περίοδο αναφοράς την περίοδο 1971-2000 (παρόν κλίμα). Τα ευρήματα παρέχουν πληροφορίες σχετικά με την αποτελεσματικότητα των πολιτικών για τις γεωγραφικές ενδείξεις ως καινοτόμα συστήματα και τις προεκτάσεις τους για τη μελλοντική ανάπτυξη πολιτικής, τονίζοντας τον πολύπλευρο ρόλο των γεωγραφικών ενδείξεων στην προώθηση της οικονομικής, κοινωνικής και περιβαλλοντικής βιωσιμότητας στην Ευρωπαϊκή γεωργία.
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Essays on textual analysis of accounting disclosures
(2024-12-12) Σωτηροπούλου, Βιργινία Αθανασία; Sotiropoulou, Virginia Athanasia
This dissertation examines initially the association of the information content of corporate accounting disclosures with firm performance and liquidity policy, and secondly, it assesses the effectiveness of two important regulations on the enhancement of the information quality of accounting disclosures (the Sarbanes-Oxley Act and the XBRL mandate). For the analysis of accounting disclosures, an algorithmic approach in the Python programming language was implemented and, in specific, the dictionary method suggested by Loughran and McDonald (Loughran and McDonald, 2011). The database that was created after the implementation of textual analysis of U.S. annual reports (10-Ks) was merged with the database containing financial data from Compustat. Furthermore, Stata software was used for the regression analyses of this thesis. This thesis includes three chapters that consist of three pillars of empirical research in the field of textual analysis of accounting disclosures. The first chapter is: “Textual analysis of accounting disclosures and firm performance”, the second chapter is: “Textual analysis of accounting disclosures and firm liquidity”, and the third chapter is: “Accounting disclosures, regulation, and firm performance”. The first chapter (Textual analysis of accounting disclosures and firm performance) consists of two self-contained essays: The first essay is: “Complexity of accounting disclosures, tone ambiguity, and firm performance: Textual analysis of readability of U.S. annual reports”, and the second essay is: “Manager’s tone of accounting disclosures and firm performance”. The first essay examines the association between readability and tone ambiguity of firms’ annual reports and performance of U.S. companies. The following hypotheses are tested: a) whether managers try to hide poor performance by disclosing complex accounting information and b) whether managers use ambiguous tone to obfuscate negative information. Specifically, the relationship between readability of financial reports and firm performance is examined. Furthermore, the impact of poor performance on the use of uncertain and modal weak tone is tested. The dictionary method is used for textual analysis to measure readability and tone ambiguity of reports. The results of textual analysis of 10-Ks are combined with financial data of U.S. firms. The findings of this study indicate that managers tend to disclose less readable reports with vague information to overshadow negative performance. The second essay (Manager’s tone of accounting disclosures and firm performance) investigates the relationship between manager’s tone in annual reports and firm performance. Specifically, the following relationships are examined: the impact of firm performance on annual reports’ tone, the association of firm performance with the managers’ decision to use positive, negative, uncertain, and litigious words in annual reports, and the impact of positive, negative, uncertain, and litigious tone of 10-Ks on firm performance. The sample consists of annual reports (10-Ks) of U.S. companies. Financial data are retrieved from the merged Compustat/Center for Research in Security Prices (CRSP) annual database. The dictionary method is used to process textual information of accounting disclosures. The findings of this study suggest that firm performance and tone of 10-Ks are significantly related. Furthermore, textual attributes of annual reports have a statistically significant impact on company’s performance. The reverse relationship is also examined, and the empirical results suggest that firm performance has a significant effect on managers’ choice of positive, negative, uncertain, and litigious words in 10-Ks. The second chapter (Textual analysis of accounting disclosures and firm liquidity) consists of two independent essays. The subject of the first essay is: “Tone, complexity, and ambiguity of accounting disclosures and corporate liquidity”, and the second essay focuses on: “The impact of litigation risk on corporate financial policy”. The purpose of the first work is to shed light firstly on the association between corporate liquidity and textual information included in accounting disclosures of U.S. companies and secondly to examine whether there is an association between complexity of annual reports, as well as ambiguity of managers’ tone and firms’ cash holdings policy. The following hypotheses are tested: First, whether the tone of accounting disclosures has an impact on firm liquidity. Specifically, legal risk, level of confidence, complexity, and optimistic tone of annual reports are examined. Second, whether more complex information in annual reports is associated with a higher level of cash holdings, and third, the association of vague corporate disclosures with the amount of cash that managers hold. Financial data are retrieved from the merged Compustat/Center for Research in Security Prices (CRSP) annual database and used along with data from textual analysis of accounting disclosures. The dictionary method of Loughran and McDonald is adopted to process textual information (Loughran and McDonald, 2011). The empirical results of this work indicate that the measures of tone of accounting disclosures examined in this study (percentage of positive, litigious, modal weak, and modal moderate words, as well as complexity of 10-Ks) have a significant relation with firm liquidity. Moreover, the findings reveal that managers that disclose more complex and vague information in 10-Ks tend to hoard cash. The second essay of the second chapter (The impact of litigation risk on corporate financial policy) examines whether there is an association between litigious risk and firm’s cash holdings. The sample consists of annual reports of U.S. companies from 1998 to 2017. Financial data from the Compustat/Center for Research in Security Prices (CRSP) database are merged with data from textual analysis of accounting disclosures. This study implements the dictionary method of Loughran and McDonald to process textual information (Loughran and McDonald, 2011). The empirical results reveal that when firms face higher legal risk, they tend to decrease the level of cash holdings. Managers’ decision to decrease corporate cash holdings when dealing with litigation risk could be interpreted as an attempt to reduce the value of the claim and additionally, to avoid being a target to future plaintiffs. The results of this study aim to equip researchers, managers, financial analysts, and investors with further knowledge as they contribute to the better comprehension and analysis of the corporate cash holdings policy. This study adds empirical evidence to a research question that is not widely examined by the literature: the impact of litigation risk on corporate financial policy. It contributes to two important strands of literature: cash holdings literature and literature of litigation risk. In addition, it enriches the measures used by accounting research by applying the textual analysis methodology of accounting disclosures. Finally, the third chapter (Accounting disclosures, regulation, and firm performance) consists of two self-contained essays. The subject of the first essay is: “The impact of SOX on the informativeness of corporate reports revisited: An analysis of textual attributes of accounting disclosures”, and the second essay examines: “The impact of the XBRL mandate on readability of U.S. annual accounting disclosures”. The first research work investigates whether there is a systematic change in the informativeness of annual reports after the Sarbanes-Oxley Act and SEC regulations of 2003, analyzing the textual attributes of accounting disclosures. The sample consists of annual reports of U.S. companies from 1998 to 2017. Financial data are retrieved from the merged Compustat/Center for Research in Security Prices (CRSP) database and analyzed along with data from textual analysis of accounting disclosures. The empirical results reveal that although the informativeness of 10-Ks’ tone has decreased after 2003, more specific measures of textual information included in annual reports are more informative after the establishment of the regulations. The assessment of the quality of accounting information after the SOX Act with more sophisticated textual analysis tools aims to equip with deeper comprehension the users of accounting information - managers, investors, analysts, auditors, and policymakers. This study augments and updates the empirical evidence on the debatable research question concerning the effectiveness of the Sarbanes-Oxley Act, examining the textual attributes of 10-Ks. It adopts a comprehensive textual analysis framework, broadening the spectrum of measures that are used in the literature. The second essay (The impact of the XBRL mandate on readability of U.S. annual accounting disclosures) aims to investigate the readability of firms’ annual reports after the implementation of the XBRL mandate in U.S. financial reporting. XBRL was adopted in three different phases. First, this research work focuses on the initial phase right after the adoption, and the implications of the mandate in the first group of firms that had to use XBRL in their 10-Ks are examined. Furthermore, the study investigates the impact of the XBRL mandate on the readability of firms’ reports after the phase-in period. The dictionary method is used for measuring readability of accounting disclosures. Financial data and ratios are retrieved from the merged Compustat/Center for Research in Security Prices (CRSP) annual database. The results of this research work indicate that the mandate had a significant impact on the readability of accounting disclosures of firms in the first phase. Furthermore, the mandate had a greater impact on the readability of 10-Ks with more quantitative disclosures. The findings suggest that the XBRL had a significant impact on firms after the phase-in period as well. This study contributes to the existing literature as it extrapolates the research regarding the impact of the XBRL mandate, which is a very significant regulation concerning financial reporting, on readability of accounting disclosures. Specifically, this research work examines the longitudinal effect of this mandate as it investigates the impact of the XBRL not only on the first adopters but on all the firms that had to implement it after the initial phase. Moreover, this study uses alternative measures of readability of 10-Ks that have not been used in prior literature to investigate these research questions, as far as I know. Finally, the implications of this study are important for researchers, managers, financial analysts, and investors as they provide a deep insight into the impact of this mandate on the quality and transparency of accounting information.
Open Access
Essays on fiscal policy
(2024-05-15) Χρυσανθακόπουλος, Χρήστος; Chrysanthakopoulos, Christos
The title of my thesis is “Essays on Fiscal Policy”. The thesis is composed of three chapters that examine current policy developments in the field of fiscal policy. It examines the medium-term effects of fiscal policy rules on fiscal outcomes, and the effects of fiscal institutions on fiscal adjustment. Moreover, it examines the cyclicality of fiscal policy and the role played by various macroeconomic, institutional, and political determinants on its conduct. More specifically, the first chapter (The medium-term effects of fiscal policy rules) builds on the idea that in the past, fiscal rules failed on their purpose. To this end, it is examined their medium-term effects, concluding that although fiscal rules lead to a fiscal easing in the medium-term, however, they lead to a more prudent fiscal policy stance when countries facing fiscal problems. The second chapter (The effects of fiscal institutions on fiscal adjustment) aims at analyzing various specific characteristics of fiscal rules and fiscal councils, assessing their impact on the likelihood of a fiscal adjustment and subsequently gauging the success of such an adjustment. The last chapter (Fiscal policy cyclicality) examines the role of fiscal rules and fiscal councils on the conduct of fiscal policy. Furthermore, for the first time, investigated the cyclicality of tax policy and its susceptibility to various factors, such as fiscal rules and fiscal councils and other macroeconomic and political factors.
Open Access
Υποδείγματα δυναμικών κοινών παραγόντων και οι εφαρμογές τους στη χρηματοοικονομική οικονομετρία
(2024-02-27) Λαδάς, Αυγουστίνος; Ladas, Avgoustinos
Στο Κεφάλαιο (1) της εργασίας γίνεται μια εισαγωγική αναφορά στην διεθνή βιβλιογραφία, στην ορολογία και στις εισαγωγικές έννοιες των επιτοκίων και των ομολόγων, μαζί με τις εφαρμογές τους. Εισάγεται η έννοια της απόδοσης ομολόγου μηδενικού κουπονιού (zero-coupon bond yield), και παρουσιάζεται η διαδικασία εύρεσης του τύπου υπολογισμού της απόδοσης (1.10), προκύπτοντας άμεσα από τον τύπο υπολογισμού της τιμής του ομολόγου (1.10). Στο Κεφάλαιο (2) της εργασίας γίνεται μια εισαγωγή σε τέσσερα υποδείγματα προσαρμογής της καμπύλης των αποδόσεων των ομολόγων μηδενικού κουπονιού (Nelson-Siegel, 1987), (Svensson,1994), (Diebold-Li, 2006) και (De Rezende-ferreira, 2013). Η εφαρμογή αυτών των υποδειγμάτων έγινε πάνω σε Ελληνικά δεδομένα, για τα οποία χρησιμοποιήθηκαν τα στατιστικά μέτρα της τετραγωνικής ρίζας του μέσου τετραγωνικού σφάλματος, του μέσου απολύτου σφάλματος και του συντελεστή προσδιορισμού για να συγκριθεί η απόδοση των υποδειγμάτων, ως προς την προσαρμογή τους στην καμπύλη των αποδόσεων των Ελληνικών ομολόγων. Προκύπτει ότι το υπόδειγμα πέντε παραμέτρων DeRezende-Ferreira έχει τη βέλτιστη προσαρμογή στα Ελληνικά δεδομένα, ανάμεσα στα υποδείγματα που αναλύθηκαν. Στη βάση της συζήτησης που αναπτύσσεται στη βιβλιογραφία αναφορικά με τα ζητήματα που ανακύπτουν από τη χρήση αυτών των παραμετρικών υποδειγμάτων προσαρμογής της καμπύλης των αποδόσεων των ομολόγων μηδενικού κουπονιού και με σκοπό την αποφυγή άστοχων εκτιμήσεων των αποδόσεων των ομολόγων μηδενικού κουπονιού της Ελληνικής αγοράς, σε συγκεκριμένες χρονικές στιγμές και ωριμάνσεις, έγινε χρήση της μη γραμμικής μεθόδου βελτιστοποίσης της Διαφορικής Εξέλιξης (Differential Evolution), η οποία αναπτύχθηκε από τους (Storn-Price, 1997), για την εκτίμηση των τεσσάρων παραμέτρων του υποδείγματος Nelson-Siegel-Svensson, με πολύ ενθαρρυντικά αποτελέσματα ως προς την προσαρμογή του υποδείγματος στα Ελληνικά δεδομένα. Στο Κεφάλαιο (3) της εργασίας γίνεται μελέτη πιθανών συνδέσεων των κινήσεων των αποδόσεων ομολόγων μηδενικού κουπονιού στις διεθνείς αγορές, ενώ γίνεται και εισαγωγή της Ελληνικής αγοράς ομολόγων στο ήδη υπάρχον σύνολο δεδομένων των υπόλοιπων διεθνών αγορών (Wright, 2011). Όπως προκύπτει, μέσα από την πρωταρχική ανάλυση, όπου γίνεται διπλή ανάλυση κυρίων συνιστωσών (Principal Component Analysis), υπάρχουν κοινοί παράγοντες οι οποίοι ερμηνεύουν σε αρκετά μεγάλο ποσοστό τις κινήσεις των αποδόσεων των διεθνών Yields. Εξάγονται τρεις Καθολικοί Παράγοντες (Global Factors) οι οποίοι μετά την ταυτοποίησή τους σύμφωνα με το υπόδειγμα Diebold-Li χαρακτηρίζονται ως Καθολικό Επίπεδο, Καθολική Κλίση και Καθολική Καμπυλότητα και τρεις Τοπικοί Παράγοντες (Local Factors) που ερμηνεύουν ένα μεγάλο ποσοστό των κοινών διαδρομών των αποδόσεων των ομολόγων των 11 διεθνών αγορών και στη συνέχεια παρουσιάζεται και η συσχέτισή τους με παγκόσμια μακροοικονομικά μεγέθη, επιβεβαιώνοντας τη σχέση του πρώτου Καθολικού παράγοντα με τον παγκόσμιο πληθωρισμό του Ο.Ο.Σ.Α., του δεύτερου Καθολικού παράγοντα με τον παγκόσμιο ρυθμό ανάπτυξης της βιομηχανικής παραγωγής και του τρίτου Καθολικού παράγοντα με τους δείκτες κινδύνου τον δείκτη εντοπισμού χρηματοοικονομικών κρίσεων και το δείκτη χρηματοοικονομικού στρες της τράπεζας του Σαιντ Λουις.
Open Access
Essays on new information technologies (social media) and labour market outcomes
(2023-09) Tzinovits, Vlantana; Τζίνοβιτς, Βλάντανα
This doctoral dissertation delves into a comprehensive analysis of the adoption and impact of new Information and Communication Technologies (ICT) on various aspects of the economy, including the development of human capital, choices regarding labour market participation, employment, unemployment, and job searching methods. This research employs detailed datasets from Greece spanning from the early 1990s to the present. By examining how ICT affects individuals, it aims to contribute valuable insights to both national and global scientific knowledge, shedding light on how ICT influences the accumulation of human capital and how this, in turn, affects decision-making in the labour market, including how individuals allocate their time. Additionally, this dissertation extends beyond the usual aspects of ICT use, such as computer and internet access, to explore other dimensions like how often ICT is used and its purpose, such as social media engagement. The dissertation is composed of three distinct essays, each focusing on aspects of the Greek labour market. The first chapter of the dissertation consists of two parts. Initially, it analyses the historical evolution of adoption and usage rates of ICT by Greek households (1993-2019). Subsequently, it explores the potential impact of adolescents’ access to a personal computer at home on various educational outcomes. The theoretical framework of analysis is based on models of human capital accumulation and digital skill development, where the possession of a personal computer at home is treated as an exogenous variable. The main objective of this research is to provide insights into the growing digital divide and its potential consequences for future inequalities, both in education and subsequently within the labour market. In the first part, we use micro-data from the Household Budget Surveys, provided by the Hellenic Statistical Authority. Within this framework, households that have acquired a personal computer at home are identified, and efforts are made to correlate household expenditures on ICT with the household’s educational expenses. By applying linear regression models and non-linear probability analysis, it was found that the relationship between education expenditures and expenditures on ICT is positive and resilient to a series of robustness tests. However, the potential bias in the results due to the inability to fully control for endogeneity in the above relationship is a challenge addressed in the second part of this chapter. For this purpose, micro-data for Greece from the Income and Living Conditions Survey (public use files of the Hellenic Statistical Authority, 2003-2019) are utilised, and modern methodological approaches for the analysis of panel data (panel event studies) are adopted. The fixed effects models, at the individual level, facilitated the extraction of appropriate robust estimators, providing evidence of causal relationships between variables (as opposed to mere correlations). Based on the analysis results, it emerged that adolescents’ access to a personal computer at home is a significant explanatory factor in analysing the variation in future educational outcomes. For example, children who do not have access to a personal computer during adolescence are 10 percentage points more likely to drop out of school compared to children with access. Additionally, it appears that the years of schooling increase in the subsequent periods following exposure to a personal computer at home. The findings in this section imply that inequalities related to computer access can significantly impact human capital development during adolescence. The second chapter of the dissertation focuses on the role of internet access in decisions related to labour market participation. The theoretical framework for this analysis is based on models of individual choice, concerning internet adoption and labour market engagement. It is worth noting that the implications of this analysis relate to issues of economic growth and income inequality. For analytical purposes, micro-data, at the individual level, for Greece are utilised from the Income and Living Conditions Survey (public use files of the Hellenic Statistical Authority, 2013-2022). The empirical investigation specifically targets the demographic of women and explores whether women’s decisions, regarding labour market participation, are influenced by their access to the internet at home. Building upon existing and well-established empirical labour supply functions for women, this chapter seeks to enhance and expand these models by incorporating variables that clearly indicate the timing of internet access from home. Subsequently, modern micro-econometric strategies for analysing panel data (panel event studies) are adopted, utilising linear probability models. These estimations include individual fixed effects to address potential bias due to unobserved heterogeneity, that often characterises women’s decisions regarding labour market participation. Based on the analysis results, it is found that women who gain access to the internet tend to increase their labour market participation rates in the periods following the acquisition of internet access. This finding appears to align with the available relevant studies in international literature. However, it is worth noting that the estimation methodology employed in this dissertation does not seem to be commonly adopted by other related studies, which typically use approximate variables. Additionally, it was also examined the extent to which labour market participation affects the acquisition of internet access. Nevertheless, the results of the econometric analysis rejected the hypothesis of a reverse causal relationship. Chapter three of the dissertation focuses on analysing the role of specific dimensions of internet usage in decisions related to the labour market. The empirical analysis delves into how individuals utilise the internet, particularly examining how they allocate their time on the internet and their specific activities, such as the use of social media. From a theoretical perspective, the examination of how individuals allocate their available time for information search and processing is anticipated to have a substantial impact on decisions related to the labour market, given that ICTs reduce the cost of job search and broaden the scope of available information. For analytical purposes, micro-level data from the Survey on the Use of Information and Communication Technologies (public use files of the Hellenic Statistical Authority, 2011-2022) are used. This data allows for the identification of individuals in various labour market states (employment, unemployment, out of labour force) while simultaneously documenting their internet usage patterns differently (e.g. frequency and purpose of internet use). Linear and non-linear probability models are employed for estimation purposes. The results of the estimations reveal that the frequency of internet usage is positively related to labour market participation and employment. Moreover, this relationship varies significantly by gender. The analysis also explores the potentially influential role of individuals’ participation in social media platforms (e.g. Facebook, Twitter) in job search. The findings indicate that this relationship is positive and statistically significant, suggesting that the need for communication and information-seeking, related to job searching, is significantly facilitated by modern ICTs.
Open Access
Emissions, temperature and economic growth. Evidence from total factor productivity and its components. The European case and the role of heterogeneity
(2023-06-28) Ρήγας, Νικόλαος; Rigas, Nikolaos
In this thesis, we employ the concept of productivity in order to examine how climate change affects economic growth and productivity in three different levels: country, European manufacturing industries and European manufacturing firms level. We also use climate characteristics as temperature and precipitation, and emissions of different pollutants to depict climate change. In that endeavor, we combine different databases and build three distinct datasets that provide detailed information to conduct our analysis. Our findings, on country level, concern a set of 115 countries for 55 years and suggest a positive effect of carbon dioxide emissions and temperature on countries' economic growth but when controlling for poor countries, the results point out that poor countries are more vulnerable compared to those that are considered rich. This is proof that climate change will widen the existing disparities and will bring an extra burden to vulnerable countries. We also provide evidence that the share of renewable energy sources in total energy is of high importance in the combat against climate change and substitution of fossil fuels with renewable energy sources should be accelerated. The industry level analysis, concerning thirteen manufacturing industries from twenty-seven European countries for a twenty year period and treat the carbon dioxide emissions as undesirable output of industries and through the use of a technological metafrontier we compute the environmental productivity, enveloping the existing heterogeneity among European manufacturing industries. We find that industrial environmental productivity has deteriorated, having a big drop during the years of crisis that could explain the average drop in productivity terms. We also test for the convergence or divergence hypothesis and results confirm the existence of convergence among European industries. The role of temperature is tested by classifying Europe in climatic zones and results indicate that the two groups have very similar patterns but the losses during crisis are greater for the countries that are considered hotter. Finally, we turn our attention to the firm level analysis in order to extract information on how different groups of emissions affect firms' environmental productivity and how the latter can be impacted by changes in environmental regulations. Findings indicate that environmental productivity growth of firms has increased in a small scale over the period of study but this increase is mainly attributed to the component that denotes innovation. We also shed light on the impact that a regulatory shock has on productivity and its components. We examine the “weak'' Porter Hypothesis and provide evidence that a well designed and enforced environmental regulation does not hinder economic growth but it promotes environmental innovation.
Open Access
Essays in financial accounting and corporate finance
Μαγεράκης, Ευστάθιος; Magerakis, Efstathios
The present thesis discusses three contemporary research topics in financial accounting and corporate finance. The first part of this doctoral thesis investigates the association between cash holdings and business strategy for non-financial and non-utility U.S. firms. The motivation for this research work stems from the critical implications for financial management, given the strategic effects of cash holdings. The study operationalizes Miles and Snow’s (1978, 2003) theoretical background and follows Bentley et al. (2013) to construct the relevant business strategy index. Through this process, two extreme business strategies are distinguished based on a firm’s resource allocation and investment behavior patterns, namely “Prospectors” and “Defenders”. The panel consists of 108,956 firm-year observations from 1974 to 2016. Following the model of Bates et al. (2009), this work employs multiple regression analysis to explore the relationship between business strategy and corporate cash holdings. The empirical results suggest that firm-level business strategy is positively related to cash holdings; thus, Prospectors are more likely to hold higher cash reserves than Defenders. Further, findings suggest that cash holding’s adjustment speed (SOA) is slower for Prospectors than for Defenders, implying that business strategy considerably influences the cash holding trend. Notably, the empirical results demonstrate that the market value of cash increases significantly only for the firms that pursue a defender strategy. The findings of this work have valuable implications for researchers by unveiling the relationship between corporate strategy and firms’ cash holdings. Specifically, the findings could be useful to financial managers and investment strategists who seek to maximize firm value through the adoption of an effective liquidity policy. What is more, the study provides support for the view that strategic choice and optimal cash management are of great importance for firms’ market value. Also, this study enriches the knowledge of business strategy’s impact on the financing policy of firms and contributes to the empirical literature on cash holdings’ determinants. In addition, it complements previous studies on U.S. firms by documenting the effect of business strategy on the speed of adjustment (SOA) in cash holdings and firm value. The second part of this doctoral thesis considers the relationship between the chief executive officer's ability and liquidity policy. Motivated by the ongoing debate concerning cash holding costs and benefits, this study attempts to evaluate management's influence on related corporate decisions. The final panel consists of 124,550 firm-year observations from U.S. incorporated firms between 1980 and 2016. The main research question is examined via fixed-effects ordinary least squares (OLS) regression analysis. Consistent with the upper echelon theory and cash holding motives, the results reveal that talented chief executive officers (CEOs) are associated with increased cash stockpiling, ceteris paribus. Further analysis shows that the relationship between CEO ability and firm cash holding is more profound for financially sound ﬁrms. In addition, firm size is likely to affect significantly the association between CEO ability and cash management. The results are robust to various sensitivity analyses and additional tests, such as GMM estimator, Granger causality test, and alternative proxies of CEO ability and cash holdings. After a thorough study of the relevant literature in the field, it emerged that, to date, there is no clear consensus about the extent to which managerial ability explains the level of corporate cash. Hence, the study provides new evidence that CEO ability is a contingent factor of corporate cash stock by empirically showing that skillful CEOs are perceived to increase corporate cash levels. The insights derived from the study are expected to advance the decision-making process of cash policies or CEO selection for business executives, investment strategists, and shareholders. Although this work is subject to limitations inherent in the use of relevant proxies, the study implements several model specifications to ensure the validity of findings in a more generic context. The third part of this doctoral thesis examines the impact of corruption on firm performance, considering the interventional role of cash holdings in the emerging market of Greece. The study is mainly motivated by the high rate of corruption in Greece, traditionally ranked as one of the most corrupt nations in the EU and Western Europe. The study utilizes a sample of 142,079 firm-year observations between 2006 and 2014. Descriptive statistics, multiple regression analyses, and various robustness checks are employed to test the empirical hypotheses. The results show that firm performance is positively related to the control of institutional corruption, implying that firms perform better when operating in a low-corruption environment. Moreover, all other things being equal, findings reveal that a firm’s cash holding strengthens the positive association between control of corruption and corporate financial performance. This research study takes a more holistic approach by considering institutional factors in conjunction with corporate financial policies and outcomes. The article illustrates how firm-level mechanisms can preclude political rent-seeking to improve corporate performance in a pervasive corrupt environment. The study's main limitation is that it focuses exclusively on a single country setting, based on the extreme-critical case's logic. Nevertheless, the findings might be helpful for business executives and regulators when implementing firms’ asset allocation strategies and anti-corruption policies. Last but not least, the study augments the relevant literature on the firm-level implications of corruption by providing new evidence for the interventional role of cash management in the context of an emerging economy.
Open Access
Non parametric estimation of the volatility of cryptocurrencies using high frequency data
(2022-09-16) Τάντουλα, Μαρία; Tantoula, Maria
In recent years, the cryptocurrency market has gained increased interest among investors, academics, policy makers and regulators all over the world, aiming to understand the unique characteristics and dynamics of cryptocurrencies price formation. The highly volatile nature and jump behavior in cryptocurrency markets as compared to traditional currencies, highlights the importance of defining a good proxy of volatility; this, will allow us to also account for the discontinuous movements in cryptocurrency prices to accurate model and forecast volatility. The overall purpose of our research is to model and forecast the volatility of cryptocurrencies, considering its critical role in many applications such as decision making, risk management and hedging. To this end, we consider the Heterogeneous Autoregressive model of Realized Volatility (HAR-RV). We utilize realized variance estimated from high frequency cryptocurrency price data. Specifically, we propose a non-parametric approach to estimate realized volatility and subsequently decompose it into continuous path variation and discontinuous path variation, to further estimate realized volatility jumps. First, we assess the predictive value of transaction activity in the Bitcoin Blockchain network, in an attempt to forecast the realized volatility of Bitcoin returns. We further explore extended versions of the HAR-RV specification, that include upside and downside jumps measures (positive and negative realized volatility jumps). The second area of interest focuses on the interconnectedness in the cryptocurrency market. To this end, we measure spillovers among major cryptocurrencies in terms of market capitalization, namely Bitcoin, Ripple, Ethereum and Litecoin. Specifically, we study the interconnectedness in the cryptocurrency market. We employ the proposed HAR-RV framework and its various extensions with the inclusion of different jump variations. In a univariate level of analysis, we examine the significance of heterogeneity and discontinuity to predict realized volatility of cryptocurrencies based on the HAR-RV framework. Additionally, we explore the spillover transmission mechanism among cryptocurrencies realized volatility by examining the relevance of realized volatility jumps and covariances. For this reason, we perform a comparative spillover analysis at a multivariate level of analysis. Multivariate HAR models (MHAR) are further examined in two versions, with and without the inclusion of covariances.
Open Access
Dynamic factor models. Applications in Greek economy and the Greek inflation
Κρίμπας, Νικόλαος; Krimpas, Nikolaos
This thesis presents and summarizes a versatile and lately developed statisticalmethod for evaluating and exploiting large datasets for time series analysis. Lately,Factor Models are widely used in macroeconomics to unveil interrelationshipsamong variables and exploit the information which is scattered across thousandsof economic variables that are available today. VAR models are widely used inmacroeconomic analysis and the estimated factors can be inserted in the VARsystem in order to achieve dimensionality reduction and avoid missing variablebias.The first part of this dissertation deals with an extensive literature review of factor models and their development through the variations that have been presentedin the international bibliography. As such, factor models have been developed inthe time domain as well as in the frequency domain, based on the assumptions onthe behaviour of the idiosyncratic component (exact and approximate) and on thebehaviour of the factors which can be static or dynamic. Moreover, an extensivereview of the empirical literature that uses Factor models on the estimation ofbusiness cycle behaviour, monetary transmission, economic condition indicatorsand forecasting topics.In the next section special emphasis is given on the estimation techniques onthe time and frequency domain along with the estimation algorithms provided. Inthe last section a static and dynamic factor model is employed on Greek inflationseries to decompose Greek inflation into common components. Static factoranalysis reveals goods prices that exhibit common variability in the Greek economyand suggests the need of estimating comprehensive inflation measures that willbe used for structural analysis and forecasting. Additionally, a dynamic factoranalysis is employed in order to decompose inflation into several price indexes thatrepresent key macroeconomic shocks in the economy. A careful examination ofthe correlation of inflation variability with the estimated indexes is provided anda thorough examination of the relative weight of anticipated monetary shocks onseveral measures of monetary policy.
Open Access
The dynamics of industrial energy and eco-efficiency performance across Europe
Στεργίου, Ειρήνη; Stergiou, Eirini
This thesis discusses two fundamental research topics in energy and environmental economics. In particular, we investigate issues and worries that are of interest to those who want to examine efficiency problems concerning the climate, energy and environmental conditions. This thesis consists of three distinct, but related essays, that concentrate on the industries of the manufacturing sector across European countries from 1995 to 2011 period, whilst their findings and conclusions could be generally implemented from researchers to policymakers. The first part of this doctoral thesis examines the concept of industrial energy efficiency for different European countries. As the economic growth of industries continuously require higher quantities of energy use, policymakers have to set specific industrial energy efficiency targets, rules and obligations so as energy intensity to be reduced and energy efficiency to be improved. Moreover, the investigation of possible factors that could potentially affect the notion of energy efficiency consist a further research question of this thesis. The results of the nonparametric approach indicate that European industrial energy efficiency declines for the majority of industries whilst the consideration that industries confront each other solely on the boundaries of a national level lead easily to overestimated energy efficiency scores. On the other hand, the econometric results suggest that path dependence phenomena and climatic features have a strong relationship with energy efficiency while energy mix displays both linear and non-linear relationship with it. The second part of this doctoral thesis analyses the levels of eco-efficiency across European industries of the manufacturing sector. The relationship between economic and ecological characteristics is important to be examined in order to evaluate the impact of industrial activities on the environment. Employing a nonparametric approach and taking into account distinct undesirable outputs from the industrial production process, it is revealed that capital and energy intensive industries perform eco-inefficiently. Furthermore, a convergence hypothesis is rejected for European industries suggesting that different steady states exist and separate policies are necessary for every country. The third part of this doctoral thesis investigates further the concept of eco-efficiency. In this sense, we incorporate in our analysis a wider spectrum of scenarios targeting at a more integrated picture regarding industrial eco-efficiency performance. The utilization of a unified technological regime and the investigation of a catch-up hypothesis disclose that the speed of eco-efficiency convergence increases throughout the years whilst the case of CO2 emissions presents an erratic behavior compared to the other undesirable outputs.
Open Access
Η δυναμική της ανεργίας στην ελληνική αγορά εργασίας
Λαμπροπούλου, Νικολίτσα; Ντεμούσης, Μιχαήλ; Ντεμούσης, Μιχαήλ; Νταούλη, Ιωάννα; Σκούρας, Δημήτριος; Ζερβογιάννη, Αθηνά; Γιαννακόπουλος, Νικόλαος; Νικολίτσα, Δάφνη; Χλέτσος, Μιχαήλ; Lampropoulou, Nikolitsa
Βασικός σκοπός της παρούσας διατριβής είναι η ανάλυση της δυναμικής της ελληνικής αγοράς εργασίας η οποία πραγματοποιείται με τον υπολογισμό των ροών εργασίας και των αντίστοιχων πιθανοτήτων μετάβασης μεταξύ των τριών κύριων καταστάσεων οικονομικής δραστηριότητας: απασχόλησης, ανεργίας και ανενεργίας. Για την πραγματοποίηση του σκοπού αυτού αντλούνται μικρο-δεδομένα από την τριμηνιαία Έρευνα Εργατικού Δυναμικού για τη χρονική περίοδο 1999-2013. Οι επιμέρους στόχοι της παρούσας διατριβής περιλαμβάνουν: α) την αναλυτική περιγραφή της ελληνικής αγοράς εργασίας για την περίοδο 1999-2013 δίνοντας έμφαση στο ποσοστό ανεργίας στο σύνολο του πληθυσμού αλλά και διαφόρων δημογραφικών ομάδων, β) τη διεξοδική εξέταση του μεγέθους, της διαχρονικής εξέλιξης και της κυκλικότητας των ροών εργασίας, γ) τον διαχωρισμό των μεταβολών του ποσοστού ανεργίας σε δύο μέρη: στον ρυθμό εισροής στην ανεργία και στον ρυθμό εκροής από την ανεργία, δ) τη διερεύνηση των παραγόντων που προσδιορίζουν τις ατομικές πιθανότητες μετάβασης μεταξύ απασχόλησης, ανεργίας και ανενεργίας εφαρμόζοντας πολυωνυμικές λογαριθμικές εξειδικεύσεις και ε) τη διερεύνηση της τάσης και της σύνθεσης της μακροχρόνιας ανεργίας καθώς και την εξέταση των παραγόντων που προσδιορίζουν τη μακροχρόνια ανεργία εκτιμώντας το υπόδειγμα της λογιστικής παλινδρόμησης. Τα βασικά συμπεράσματα που προέκυψαν από την παρούσα έρευνα είναι τα εξής: Η ελληνική αγορά εργασίας χαρακτηρίζεται από ένα πρωτόγνωρα υψηλό ποσοστό ανεργίας που εκτινάχτηκε στο 27.8% στο δεύτερο τρίμηνο του 2013 αλλά και από ένα δραματικά υψηλό ποσοστό μακροχρόνιας ανεργίας που αγγίζει το 66.8%. Η πιθανότητα εύρεσης εργασίας που αντιμετωπίζει ένας άνεργος έχει μειωθεί σημαντικά από 26% πριν την κρίση στο μόλις 10.3% στο δεύτερο τρίμηνο του 2013. Τόσο ο ρυθμός εισροής στην ανεργία όσο και ο ρυθμός εκροής από την ανεργία είναι εξίσου σημαντικοί παράγοντες στην εξήγηση των διακυμάνσεων της ανεργίας. Στην αρχή της ύφεσης, ο ρυθμός εισροής στην ανεργία υπερισχύει ενώ ο ρυθμός εκροής από την ανεργία κυριαρχεί σε μεταγενέστερες φάσεις της ύφεσης. Μεγαλύτερη πιθανότητα μετάβασης από την απασχόληση στην ανεργία έχουν: οι γυναίκες, οι νέοι 15-24 και 25-34 ετών, οι κάτοχοι πρωτοβάθμιας εκπαίδευσης, οι άγαμοι, αυτοί που εργάζονταν στον κλάδο των κατασκευών-ορυχείων-λατομείων και οι μισθωτοί. Μεγαλύτερη πιθανότητα μετάβασης από την ανεργία στην απασχόληση έχουν: οι άνδρες, οι νέοι 15-24 και 25-34 ετών, οι αλλοδαποί, οι κάτοχοι τριτοβάθμιας εκπαίδευσης. Τέλος, περισσότερο εκτεθειμένοι στον κίνδυνο της μακροχρόνιας ανεργίας είναι: οι γυναίκες, οι άνεργοι 45 ετών και άνω, οι άγαμοι, οι κάτοχοι πρωτοβάθμιας εκπαίδευσης, όσοι δεν διαθέτουν εργασιακή εμπειρία καθώς και αυτοί που σταματούν την εργασία τους λόγω παραίτησης.
Open Access
Quality of work in online labor markets : an empirical study in paid crowdsourcing environments
Μουρελάτος, Ευάγγελος; Τζαγκαράκης, Μανώλης; Τζαγκαράκης, Μανώλης; Δημάρα, Ευθαλία; Καρακαπιλίδης, Νικόλαος; Mourelatos, Evangelos
Over the years a great number of different websites have emerged (e.g. Amazon Mechanical Turk, Crowdflower, Microworkers) that offer crowdsourcing services which focus on specific tasks, which range from general purpose simple chores to research and development assignments. As the number of crowdsourcing websites is today rapidly increasing, research efforts concentrate on examining and analysing this new way of providing labor, while, at the same time, addressing problems that may arise. The overall purpose of our research, conducted at the Department of Economics of the University of Patras, is to investigate various economic aspects of this new form of work currently becoming all the more important. The emphasis is in particular on the issue of quality in such labor markets. For that reason, as a first step, our aim is to review and analyze existing websites providing crowdsourcing services in an attempt to establish a framework that will allow systematic discussion, comparison and assessment of their overall performance. Moreover, despite the increased popularity of the crowdsourcing online activity, little is also known on the quality of output and the associated determinants of a task-specific outcome. In this thesis, we investigate also the impact of cognitive and non-cognitive skills on the quality of a task-specific outcome by conducting an experiment on a popular crowdsourcing platform. Using linear regression models and controlling for a wide set of individual characteristics and country-specific indicators, we found that the performance of workers depends on cognitive skills, personality traits and work effort. Overall, we find that micro-workers with higher levels of neuroticism perform worse, a finding that is in line with relevant studies in traditional labor markets. These results are expected to gain insights on the effective role of worker attributes in online labor markets.
Open Access
Income effects on willingness to pay measures in the water directive
Τυλλιανάκης, Εμμανουήλ; Σκούρας, Δημήτρης; Σκούρας, Δημήτρης; Τζελέπης, Δημήτριος; Κουνετάς, Κωνσταντίνος; Κουρλιούρος, Ηλίας; Κουντούρη, Φοίβη; Tyllianakis, Emmanouil
Economic policy and the subsequent decision-making progress were two of the main points of emphasis of this thesis. Given the novelty of the layout of the WFD which included and demanded a heavy “portion” of policy-making to be informed by economic theory, welfare changes and economic theory were considered in this volume. As the review of the WFD is coming in 2019, this thesis aims to contribute to the evaluation of the Directive and to inform future Directives and measures between the member states. The results from the abatement costs for the four different mitigation measures presented in chapter 4 showed that abatement costs, regardless of mitigation measures and/or climate change scenarios, proved that costs were too high. Costs were high in terms of implementing the various mitigation measures and they also burdened disproportionately more farmers than any other type of stakeholders. Interestingly enough, the WFD followed an approach that can be described “anthropocentric” in its core, by placing human welfare ultimately as the decisive factor in decision-making processes related with the WFD. Although the attainment of GES across the EU and in all water bodies was the ultimate goal of the Directive, the primary focus was human welfare. WFD mandates make clear that if the costs are too high for some groups of stakeholders, if achieving GES proves to disruptive for a part of an RDB or it requires serious investment from the side of local governments that would lead to substantial welfare loss for local stakeholders, then, implementing the WFD was not required. Furthermore, Marginal Abatement Cost Curves (MACCs) in every mitigation measure were high and reductions in fertilizers (thus, costs) had to be substantial in order for their respective MACCs to deviate from any other agri-environmental measure proposed in earlier EU legislation, such as the Common Agricultural Policy (CAP). This raises the question on the real impact of the WFD, both in terms of novelty in the policy side but also in terms of efficiency given the extent of research, funds and time devoted to the designing, assessing, valuing, implementing and monitoring the whole directive and its progress across Europe. These results though are also indicative of the pre-existing water status of the Louros’ watershed which was in a good status and achieving GES required significant start-up costs that “derailed” MACCs. Of extreme interest is the focus of the EU to fund water-related issues in member states. It is evident that the E.U. invested heavily on the implementation of the WFD. There are no available figures of the total spending from the E.U.’ or from member states’ part. Still, evident of how invested the Community was to the Directive is the total allocation of funds that member states could “tap into” to fund projects aiming at various issues related to water resources. There were various funding opportunities, each aiming to provide financial aid to member states as they dealt with the implementation of the WFD and with issues to their water resources. The Cohesion Policy Fund for the period 2007-2013 had a total budget of 344 billion Euros with the goal to fund “capital-intensive investments in water infrastructure and help EU Member States comply with water legislation.” . The primary focus of the Fund was to divert funds to countries whose Gross National Product (GNP) was below 90% of the E.U. average. The Fund’s focus was mainly on water management (namely: prevention of disaster and risks and improving efficiency). Similar to the Cohesion Policy Fund but with a considerably smaller budget is the “Life + Funds” initiative. This focuses on supporting the implementation of the WFD as well as raising awareness on water-related issues. The total budget for the period between 2007 and 2013 was 1,7 billion, with small country-wide projects being awarded sums up to 1 million Euros. It needs to be noted that these sums of money were not ultimately spent by member states, there were available, if specific terms were met. Their significance is that they demonstrate the level of financial commitment from the E.U.’s part to the issue of water. The findings of the disproportionality analysis revealed which groups were the primary cost bearers and the hydrological modeling along with the various climate change scenarios provided useful insights on the types of stressors on the environment. Although the proposed mitigation measure (mitigation measure 2) was the least “invasive” to the environment, still it yielded a negative benefit in the CBA. This can be attributed to the nature of the mitigation practices and to the existing water quality of the case study area. The mitigation practices were rather “vertical” in their nature, being expensive for the farmers and all of their costs being mandatory to occur every year. The water quality of the Louros catchment was not in a bad status in terms of ecological status but still, for it to achieve GES required considerable economic costs. Hypothetically, if other types of mitigation practices were more appropriate given the economic practices taking place in the Louros catchment, MACCs could be less steep and yielding considerably different values than the “no-change” scenario. Thus, the “technology” of cultivating nitrogen fixing legumes on set aside land ensures that, under any climate change scenario, abatement will be higher at any chosen cost level. The cost-benefit analysis in all scenarios did not yield positive Net Present Value (NPV). Although this is not desirable in environmental policy and economics, still, these results can be of great use. One of the most evident deficiencies in the CBA in chapter 6 of this thesis was the misrepresentation of benefits. Only the residents of the three municipal units were considered to be benefited from achieving GES when the river offers a multitude of services to non-residents as well. Apart from the energy generation from the hydroelectric dam at St. Georgios which provides electricity to an area exceeding the boundaries of the Louros catchment, the river has recreational value since activities such as rafting, canoeing, angling and hiking take place there. One can only assume that with the Ionia Odos highway being almost complete, even more visitors will be able to access Western Greece and Louros will attract even more visitors. Furthermore, even direct benefits from achieving GES could be expanded to residents of areas more distant than Arta and Preveza, such as residents from Ioannina, the largest residential area of northwestern Greece. Environmental goods are notoriously difficult to assess as, usually, there are no markets for them to be bought and sold. Neoclassical economic theory allows for the creation of “quasi” markets by assuming that there are close substitute goods that can be traded in the hypothetical markets that are created. This allows for the exchange of goods, achieving equilibrium and the estimation of prices and surpluses. The focus of this thesis is on the environmental good of water quality, (not just water, either drinking, bating, saline or freshwater) with a particular focus on freshwater (although the WFD includes coastal waters in its assessment as it requires the GES to be achieved at least up to 6 nautical miles from the coast of member states). The reason behind that was to establish a well-defined and easily conceivable good whose introduction to a hypothetical market would be relatively easier than other more broadly defined environmental goods. Additionally, as the Eurobarometer studies of 2009 and 2012 show, there is an interest from the public on the issues that affect water quality, amongst others. We also were able to utilize the substantial literature already existing in the field of environmental goods, ecosystem services and environmental economics and valuation, especially the fact that several primary studies on the valuation of freshwater quality already existed in a European context. Environmental goods are greatly debated in terms of their nature, if they are normal, inferior or luxury goods. Depending on the value of the price elasticity, goods are classified as above. The focus of this thesis though revolves around policy measures and how these impact human welfare and therefore examining distributional effects of policy measures such as the WFD was more appropriate. This is achieved through the calculation of the elasticity of WTP which informs on the specific issue of the distribution of benefits across poor and rich households, determining which policy measures are “pro-poor” (elasticity of WTP lower than 1), “pro-rich” (elasticity of WTP higher than 1), or equally distributed (elasticity of WTP equal to 1). The results from chapter 5 of this thesis contribute on this discussion by yielding robust results in terms of magnitude, sign and level of significance of the coefficients, even when the sample is trimmed by as much as 15% from below or above or when certain influential case studies are withdrawn. In most of the econometric methods used, elasticities of WTP were above 1 and up to around 1,5. These results though are dependent on the income measured used to estimate WTP. When official data were used, obtained by Eurostat for the respective NUTS 2 regions of the primary studies, income elasticity of WTP were above 1 meaning that the proportion of WTP to the income measure is increasing as income rises and thus, achieving GES has proportionately higher benefits to richer households than to poorer households. If the explanatory variable of WTP is the income reported by the primary studies, then, income elasticity is below the unit and benefits from achieving GES benefit more the poorer households than the rich ones. These findings reveal the serious policy implications of selecting reliable income estimates and contribute to the debate of whether selecting income as an explanatory variable of WTP for environmental goods and services is required. Furthermore, the policy implications about the distributional effects on income by achieving GES strengthen the views of Hokby and Sorderquvist (2003) that when such distributional concerns are the subject of a cost-benefit analysis, the introduction of weights or at least a sensitivity analysis is required for policy appraisal. This finding also aligns with the broader discussion started by Aaron and McGuire (1970) on the distributional nature of public goods and the wider benefits and positive externalities that they offer. Aaron and McGuire also make the case that the very nature of public goods affects more the “working poor”, an issue to be considered in public budget design and spending. This thesis went a step “backwards in its last chapter, attempting to combine environmental services and the results of environmental and ecological monitoring in an effort to explain human behaviour. We did so by using EU-wide data concerning perceptions of EU citizens and biophysical, chemical, geomorphological and ecological data (the product of new and more demanding monitoring practices as new EU directives such as the Water Framework Directive, the Nitrates Directive and the Marine Strategy Framework Directive). The purpose behind it was to have an overall view on how these ambitious mandates which are deployed to augment human welfare, while having a great financing, implementation and monitoring costs, fare in the perceptions of individuals. Given the heightened willingness of the EU Commission to include public consultation in the designing stages of such directives, citizens’ input becomes more valuable. The simple question behind chapter eight was “what do people view as risks to the water environment of their country, given the actual status of their region’s water bodies”? The responses gave us robust estimates of risk perceptions. Risk perceptions on water issues appear to be determined by various factors, all of them not depending significantly though on the status of the respondents’ water bodies. Instead, pre-existing environmental awareness, high levels of education and sensitivity towards the environment appear to be more determining factors of formulating risk perceptions. Overall, risk perceptions for EU citizens are not affected by the status of the water bodies in their region so much, but rather by the overall pressures in the water environment of their country, and by their pre-existing beliefs and cognitive processing methods. Such findings are mostly consistent with the wide literature of pressures to the environment, most notably perceived pressures from climate change, and shed light in the assessment of top-down policies such as the Water Framework Directive. The key recipients of the benefits of such policies appear to be little informed of the actual pressures of their regions, despite the fact that they perceive themselves as being informed and aware. Additionally, although management of water bodies is mostly assigned to regional bodies (such as the relevant water management plans designed and delivered by each EU prefecture having water bodies), the design of those directives is conducted in an EU-level and many times appears distant of what EU citizens demand. The inclusion of public consultation as an important factor in such policies appears at first to be solving such problems but the findings of chapter 7 demonstrate that the public doesn’t take much into account the actual problems in their regions’ water bodies, or that there is still considerable lack of information for those issues in EU prefectural-level. This thesis heavily relies on the results from two hydrological and land-use models. It used official data on water quality indicators, collaborating with scientific university departments and applying them to the Louros catchment. Although the availability of biophysical and chemical data was not always up-to-date (few data collection points and data sometimes coming from older studies), still, they were enough to inform the INCA (for nitrates and phosphorus) hydrological model to simulate the P concentrations in water under the baseline and the alternative mitigation measures. The INCA( N and P) model prides itself for incorporating as many aspects as possible that affect the water environment such as climate conditions (especially precipitation and temperature), physical conditions (slopes, elevation), soil conditions (especially soil chemistry), hydrography (density of watercourses and manmade interventions such as the irrigation network and drainage ditches). The main drivers and focus of the model was nutrient and sediment transport. The complexity of the model also allowed for climate change scenarios to be incorporated later on on the analysis to project the effects of policy measures according with the four main IPCC (2007) scenarios. Land-use was modeled after combining the four different mitigation measures that focused both on agricultural practices but also in the types of cultivations, combining “practice” and “technology”. These mitigation measures and their future projections were modeled after the IPCC scenarios and the country-specific measures published from the Central Bank of Greece. The results were particularly interesting, especially in terms of water quality. Implementing the WFD mandates would yield only marginal improvements in water quality across the catchment as it was already in good status. Additionally, regardless of the climate change projections, all mitigation measures reduced, again, only marginally the nitrate and phosphorus concentrations.
Open Access
Μελέτη της εταιρικής περιβαλλοντικής λογιστικής και διαχείρισης στην Ελλάδα
Αλεξόπουλος, Ηλίας; Τζελέπης, Δημήτριος; Τσεκούρας, Δημήτριος; Κουνέτας, Κωνσταντίνος; Σύψας, Παναγιώτης; Κουμανάκος, Ευάγγελος; Γεωργόπουλος, Αντώνιος; Βενέτης, Ιωάννης; Alexopoulos, Elias
Η αυξανόμενη πίεση από τα διαφορετικά ενδιαφερόμενα μέρη για την ανάληψη δράσεων μείωσης του εταιρικού περιβαλλοντικού αποτυπώματος, έστρεψε την εταιρική κουλτούρα και στρατηγική προς την επιδίωξη μιας βιώσιμης ανάπτυξης. Στο πλαίσιο αυτό μελετάται για πρώτη φορά, βάσει Ελληνικών λογιστικών δεδομένων, η αναγνώριση των παραγόντων διαμόρφωσης του ύψους της εταιρικής περιβαλλοντικής αποκάλυψης, η σύνδεση της εταιρικής περιβαλλοντικής επίδοσης με την τεχνική αναποτελεσματικότητα καθώς και η ύπαρξη αιτιακής σχέσης μεταξύ περιβαλλοντικής και χρηματοοικονομικής επίδοσης. Χρησιμοποιώντας ανάλυση περιεχομένου ερευνώνται το επίπεδο εταιρικής περιβαλλοντικής αποκάλυψης και οι προσδιοριστικοί του παράγοντες όπως αποτυπώνεται στις λογιστικές καταστάσεις με τα προσαρτήματά τους. Στη συνέχεια, βάσει της προσέγγισης του στοχαστικού ορίου των Battese και Coelli (1991), ερευνάται η σύνδεση του επιπέδου περιβαλλοντικής επίδοσης με τη τεχνική αναποτελεσματικότητα. Το τελευταίο εμπειρικό κεφάλαιο ασχολείται με την ύπαρξη ενός «ενάρετου κύκλου» μεταξύ περιβαλλοντικής και χρηματοοικονομικής επίδοσης βασιζόμενο στη γενικευμένη μέθοδο των ροπών όπως προτείνεται από τους Arellano και Bond (1991) σε επίπεδο μεταποιητικών μονάδων. Τα αποτελέσματα των σχετικών εμπειρικών κεφαλαίων αποκαλύπτουν αφενός τη χαμηλή αντίληψη των Ελληνικών επιχειρήσεων της σημασίας της περιβαλλοντικής αποκάλυψης. Αφετέρου, η απόφασή τους για παροχή σχετικών στοιχείων σχετίζεται με την ανάγκη μείωσης της ασυμμετρίας πληροφόρησης, τον κίνδυνο αποκάλυψης ευαίσθητων πληροφοριών, την έκθεση στη δημοσιότητα καθώς και την ύπαρξη μεγάλης εταιρικής βάσης και απαρχαιωμένου εξοπλισμού. Επίσης, η εισαγωγή της περιβαλλοντικής διαχείρισης ως μέρος της εταιρικής διακυβέρνησης καθώς και η ύπαρξη μιας συγκεκριμένης εταιρικής περιβαλλοντικής πολιτικής μειώνουν την τεχνική αναποτελεσματικότητα. Κατά τη μελέτη της αιτιώδους σχέσης μεταξύ περιβαλλοντικής και χρηματοοικονομικής επίδοσης η ύπαρξη ενός «ενάρετου κύκλου» δεν επιβεβαιώθηκε καθώς τα κόστη από την ανάληψη δράσεων βελτίωσης της περιβαλλοντικής επίδοσης υπερκαλύπτουν τα οφέλη που προκύπτουν.
Open Access
Studies on break detection in financial time series volatility
Χατζηκωνσταντή, Βασιλική; Βενέτης, Ιωάννης; Τζελέπης, Δημήτριος; Τζαβαλής, Ηλίας; Δημαρά, Ευθαλία; Ζερβογιάννη, Αθηνά; Τσεκούρας, Κωνσταντίνος; Καρόγλου, Μιχαήλ; Chatzikonstanti, Vasiliki
The aim of this thesis is to provide an econometric analysis on volatility dynamics by examining the implications of structural changes. Specifically, it analyses how the existence of structural changes may influence the volatility persistence and/or long memory in financial time series. In the second chapter a Monte Carlo simulation experiment it is employed to examine the performance of a CUSUM type statistic for break detection. In particular, we study the statistical properties of a non-parametric approach for single and multiple breaks detection by employing a large number of different long run variance estimators and different types of breaks. However it cannot be supported the adoption of a single long run variance estimator to inflate the algorithm for the break detection. In the third chapter we examine the effects of structural changes on the volatility dynamics of a market has been basically unexplored in the context of structural change, the Athens Stock market. A CUSUM type statistic is used for the break detection. Once the breaks are accounted for the volatility persistence is substantially reduced. The fourth chapter focuses on the interaction between structural changes and outliers on the volatility. To this end, it employs a wavelet-based outlier detection method along with a non-parametric break detection approach. The examination of GARCH models reveals that the series are highly persistent, if breaks are not accounted for, while ignoring outliers induces biases to GARCH parameters estimates. The last chapter provides empirical evidence whether long memory in daily log-range series could be explained by the presence of structural changes. A multiple break model that assumes abrupt shifts or jumps in volatility and a smooth transition model that allows abrupt shifts, smooth shifts or a combination are employed to detect and characterize breaks. The analysis revealed that long memory could be considered to some extent spurious. When accounting for the level shifts, the evidence in favour of long-memory in the log-range series is no longer supported.
Open Access
Essays in efficiency and productivity analysis under technology heterogeneity regimes
Χατζησταμούλου, Νικόλαος; Τσεκούρας, Κωνσταντίνος; Σκούρας, Δημήτριος; Κουνέτας, Κωνσταντίνος; Τσιώνας, Ευθύμιος; Χάλκος, Γεώργιος; Μούρτος, Ιωάννης; Broadstock, David; Chatzistamoulou, Nikolaos
The ample interest of every strand in Efficiency and Productivity Analysis during the last decades has been placed on unravelling the mechanisms and identifying the sources of heterogeneity among the units under consideration so as to guarantee to the most possible extent that the benchmarking process takes places among similar Decision Making Units. Regarding the sources of heterogeneity have been scouted among the ownership scheme of the firm, the managerial ability, the size of the firm, the technology the production entity has access to among others. The latter could be further attributed to resource endowments, productivity differentials, regulations over the production process and past achievements which determine to a significant extent, future developments. All in all, these factors have been explored under the label of technological heterogeneity. Efficiency analysis‘ empirical literature has been beneficiated by the introduction of metafrontier, almost a decade ago, which envelops the individual frontiers and accounts for all the possible heterogeneity among the units under examination since the latter are evaluated against the available state of knowledge.
Open Access
Εξελικτικές οικονομικές μέθοδοι ανάλυσης, συσπείρωσης και παραγωγικότητας επιχειρήσεων
Σταυρόπουλος, Σπυρίδων; Σκούρας, Δημήτριος; Τσεκούρας, Κωνσταντίνος; Ψαλτόπουλος, Δημήτριος; Burger, Martijn; Wall, Ronald; Παπαδασκαλόπουλος, Αθανάσιος; Δημαρά, Ευθαλία; Stavropoulos, Spyridon
H παρούσα διδακτορική διατριβή έχει σκοπό να καλύψει ερευνητικά ερωτήματα που σχετίζονται με τις οικονομίες συγκέντρωσης και την κερδοφορία των επιχειρήσεων σε συνιστώσες σε επίπεδο επιχειρήσεων, τοποθεσιών και βιομηχανιών. Στο πρώτο μέρος αμφισβητούμε την ικανότητα των οικονομιών συγκέντρωσης να τονώνουν την κερδοφορία και την υγιή χρηματοοικονομική αποδοτικότητα των επιχειρήσεων. Καθορίζουμε ένα συγχρονικό δείγμα περίπου 410.000 επιχειρήσεων οι οποίες δραστηριοποιούνταν σε όλους τους υποτομείς της μεταποιητικής βιομηχανίας και βρίσκονταν σε 191 περιφέρειες του 2ου επιπέδου της ονοματολογίας των εδαφικών στατιστικών μονάδων (NUTS 2) 15 κρατών μελών της Ευρωπαϊκής Ένωσης, το 2005. Για κάθε επιχείρηση, μετράμε δύο δείκτες κερδοφορίας και έναν δείκτη αποδοτικότητας της εργασίας. Βρίσκουμε ότι το μέρος της διακύμανσης των δεικτών κερδοφορίας και αποδοτικότητας της εργασίας, το οποίο αποδίδεται στις περιφέρειες, είναι πολύ μικρό. Επίσης, ορισμένα δοκιμασμένα πολυεπίπεδα μοντέλα αποδεικνύουν ότι η ποσοτική επίδραση της περιφερειακής εξειδίκευσης είναι πολύ μικρή, παρ' όλο που είναι στατιστικά σημαντική. Τα αποτελέσματα είναι ανθεκτικά σε πιο περιορισμένες γεωγραφικές κλίμακες και υποτομείς. Ωστόσο, το 2ο επίπεδο NUTS παραμένει η κυριότερη χωρική κλίμακα σχεδιασμού και εφαρμογής της περιφερειακής πολιτικής της Ευρωπαϊκής Ένωσης. Τα αποτελέσματά μας επωφελούνται από τη δύναμη και την ασφάλεια που εξασφαλίζει το μεγάλο εύρος του δείγματος και αποτελούν πρόκληση για τις συμβατικές προσεγγίσεις της έρευνας της συγκέντρωσης και της πολιτικής για τους συνεργατικούς σχηματισμούς. Στο δεύτερο μέρος θέτουμε το ερώτημα: γιατί μερικές επιχειρήσεις είναι περισσότερο αποδοτικές από κάποιες άλλες; Μία προσέγγιση για την εμπειρική διερεύνηση αυτού του ζητήματος είναι ο διαχωρισμός της διακύμανσης της κερδοφορίας των επιχειρήσεων σε συνιστώσες σε επίπεδο επιχειρήσεων, τοποθεσιών και βιομηχανιών. Παρόλο που έχει τεκμηριωθεί εκτενώς το γεγονός ότι η σποραδικότητα των δεδομένων στις μελέτες της διάσπασης της διακύμανσης ενδέχεται να οδηγεί στην υπερεκτίμηση ορισμένων συνιστωσών της διακύμανσης, οι μελέτες της στρατηγικής διοίκησης οι οποίες έχουν διερευνήσει τη φύση των διαφορών που παρατηρούνται στην κερδοφορία των επιχειρήσεων, δεν έχουν δώσει μεγάλη προσοχή στις προϋποθέσεις σε σχέση με το μέγεθος των δειγμάτων τους. Διεξάγουμε μια μελέτη μετα-ανάλυσης της παλινδρόμησης και μια μελέτη ελέγχου και καταλήγουμε στο συμπέρασμα ότι η μεταβλητότητα που παρατηρείται στα αποτελέσματα των παλαιότερων μελετών εξαρτάται -σε σημαντικό βαθμό- από τον αριθμό των παρατηρήσεων που περιλαμβάνει η κάθε ομάδα, σε μια ορισμένη συνιστώσα μιας μελέτης. Ως εκ τούτου, θα πρέπει να είμαστε προσεκτικοί κατά την εξαγωγή γενικών συμπερασμάτων από παλαιότερες μελέτες της διάσπασης της διακύμανσης οι οποίες έχουν διερευνήσει την κερδοφορία των επιχειρήσεων, στον τομέα της στρατηγικής διοίκησης. Τέλος η έννοια της σχετικής διαφοροποίησης των επιχειρήσεων που προσελκύει όλο και περισσότερο το ενδιαφέρον των ερευνητών στις συζητήσεις σχετικά με τον χαρακτήρα της περιφερειακής ανάπτυξης και τη φύση της διάδοσης της γνώσης σε τοπικό επίπεδο αναλύετε. Με αυτή την έννοια, αμφισβητείται η υπόθεση ότι καθαυτοί οι εξωτερικοί παράγοντες Jacobs προωθούν τη διάδοση της γνώσης και υποστηρίζεται ότι «η γνώση θα διαδοθεί αποτελεσματικά μόνο εάν υπάρχει συμπληρωματικότητα μεταξύ των τομέων, από πλευράς κοινών ικανοτήτων». Η οικονομική λογική του εν λόγω επιχειρήματος στηρίζεται στην έννοια της επαρκούς γνωστικής εγγύτητας. Ευρήματα σε αυτό το πλαίσιο αποδεικνύουν ότι οι μεγάλες διαφορές ανάμεσα στις υπάρχουσες και στις νέες γνώσεις εμποδίζουν την αποτελεσματική επικοινωνία, καθώς και ότι η διαδραστική μάθηση λειτουργεί καλύτερα στην περίπτωση που η γνωστική απόσταση μεταξύ των εταίρων δεν είναι υπερβολικά μεγάλη. Συνεπώς, αυτό το σκεπτικό επικεντρώνεται συγκεκριμένα στην περιφερειακή σύνθεση των βιομηχανικών τομέων και διαχωρίζει τις επιδράσεις των εξωτερικών παραγόντων Jacobs, αφενός στις επιδράσεις της σχετικής διαφοροποίησης των βιομηχανικών τομέων και αφετέρου, στις επιδράσεις της μη σχετικής διαφοροποίησης των βιομηχανικών τομέων.