Browsing Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ) by Title
Now showing 1 - 20 of 98
Results Per Page
- ItemOpen AccessA managerial accounting framework for the performance measurement and management of profit and cost centers of food – retailing organizations in dynamic environments
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Λαμπρόπουλος, Ιωάννης; Lampropoulos, IoannisThe present thesis develops an operational efficiency managerial accounting framework for retailing networks in dynamic environments. The research is motivated by the fact that during adverse economic conditions, retailers focus on improving the operations of their stores, making operational efficiency a strategic priority for them. Also, when the economic environment gradually begins to improve, the management needs the appropriate measurement tool to properly evaluate the efficiency effects of alternative growth modes implemented, either through the opening of new stores or acquiring other store networks under a merger and acquisition (M&A) strategy. The benchmarking analysis based on the advanced bootstrapped DEA tool, is motivated and illustrated utilizing a unique set of micro-data on 106 retail stores of a representative Greek Super Market (S/M) retailing network that operated under a highly recessionary and competitive environment, undertaking a systematic monthly-based analysis over two recessionary years (2012-2013) with a gradual improvement of the operating environment the year after (2014). The proposed managerial framework with the joint use of bootstrap DEA, second-stage regression analysis, radar analysis and decision tree algorithm: a) locates properly the efficiently best and worst performers over time b) identifies the main sources of inefficiency c) proposes efficiency improvements at the operational and strategic level. Additionally, efficiency measurements in different dimensions (i.e. operational and profit) show that efficiency is unequally distributed over recession and between different types of store sizes (i.e., large stores being more efficient than small and medium ones) while higher operational efficiency tends to be related to higher profit efficiency. Also, the undertaken efficiency analysis during normal economic conditions provides evidence that compared to organic growth, M&A result in lower operational efficiency. The proposed performance managerial framework offers a managerial tool for evaluating the efficiency of S/M retailing networks in turbulent times while it provides significant managerial implications for growth purposes when economic conditions are normalized.
- ItemOpen AccessAirport business excellence : a holistic approach to performance management
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Παράσχη, Παρασκευή; Γεωργόπουλος, Αντώνιος; Γεωργόπουλος, Αντώνιος; Καλδής, Παναγιώτης; Παπαθεοδώρου, Ανδρέας; Πέππας, Παύλος; Πολυχρονίου, Παναγιώτης; Παπαδημητρίου, Δήμητρα; Τσαγκανός, Αθανάσιος; Paraschi, ParaskeviAviation business is a primary impetus for the global economy and airports pose a central position in the aviation system. Air transport restructuring of the last three decades has increased the demand for performance improvement in all nodes of the air transport pipeline. Nevertheless, airports are still treated more like infrastructures rather than enterprises, with their efficiency almost exclusively measured in operational and financial terms. The current study is the first known attempt to deal with airport performance in a holistic manner. We approach airports as integrated business ecosystems and we borrow concepts from ecology science to explore their interacting components. We first investigate airports biotic factors, i.e. all living airport participants and their relations. To do so, we develop a novel Airport Business Excellence Model (ABEM) which assesses airport performance using twelve groups of criteria: Leadership, Strategy, HRM, Suppliers and Resources, Partners and Customers, Processes, Products and Services, People results, Operational results, Quality results, Customer results, Society results and Financial results. ABEM was applied to a pluralistic sample of 143 airports in 92 states all over the world. The total performance score derived from ABEM application was subsequently associated with abiotic determinants of the external environment, in order to draw the overall picture of Airport Ecosystem Performance. The study results indicate that airport biotic factors weave a complex nexus of interactions, with Leadership and Strategy displaying the broader impact. Rather surprisingly, Financial results were not considered of primary importance contrary to the People and Operational results that were estimated as more crucial to achieving airport excellence. Regarding the environmental abiotic factors, our findings further support and extend the existing literature, concluding that low seasonality (50-60%), a big airport size between 60 and 80 million WLUs and a combination of Light-handed/monitoring with Dual Till regulation scheme have a positive contribution to the airport performance. On the contrary, hosting no airlines as home base, having a mixed ownership/public management or public ownership/private management, the absence of any Performance Management System and the combination of public ownership with RoR regulatory framework have a negative influence. Finally, we studied the joint impact of the biotic and abiotic performance determinants, finding that the contribution of the software factors is more significant than the effect of the business surroundings to the overall performance of the airport ecosystem.
- ItemOpen AccessAntecedents and consequencies of mobile electronic commerce use, marketing activities and performance in the business-to-business context
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Ντάρλας, Γεράσιμος; Ntarlas, GerasimosThis study was prepared at the University of Patras in the Department of Business Administration and attempt to contribute increasing knowledge by examining the factors that may contribute to the successful implementation of M-Commence marketing in the case of corporate clients. Mobile commerce is the evolution of e-commerce, following the widespread use of mobile devices. It is now a given that mobile devices are an important element of the new, digital economy, given the revolution of wireless networks and the great growth of M-commerce. Mobile commerce (via Smartphones) and Mobile marketing is becoming increasingly popular and important. Academic research on mobile marketing is expanding at a rapid pace, prompted by widely publicized, too optimistic forecasts of future success of mobile marketing and success stories of mobile marketing initiatives. In this context, mobile applications are the result of a series of actions, the adoption of several best collaboration practices, the development of schedules and risk management, among others. In this context, an attempt is made to examine the factors that may contribute to the successful implementation of M-Commence marketing.
- ItemOpen AccessBig data analysis in humanities and economics with machine learning techniques and use of cloud computing technologies
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Θεοδωρακόπουλος, Λεωνίδας; Theodorakopoulos, LeonidasSentiment Analysis has been extensively investigated in recent years as a method of human emotions’ classification to specific events, products, services etc. It is considered as a very important problem, especially for organizations or companies who want to know the consumers’ view about their products and services. In combination with the evolution of social media, it has been established as an interesting domain of research. Through social media, people tend to express their opinions or feelings, such as happiness or sadness on a daily basis. Thus, the vast amount of available data has made the existing solutions inappropriate and the need for automated analysis methods is imperative. In this thesis, it was examined sentiment polarity analysis on Twitter data in a distributed environment, known as Apache Spark. More specially, in this thesis are propose three classification algorithms for tweet level sentiment analysis in Spark due to its suitability for Big Data processing against its predecessors, MapReduce and Hadoop. Also The research to study the effects of economic policy uncertainty on the return volatility of stock with data from the largest banking institutions in Greece. Volatility is constructed using intraday data, the research period extends over a period of about thirteen years, more specifically from January 5, 2001, to June 30, 2014. This period contains various phases of the market such as stock market crashes along with stock market booms (e.g. the financial crisis of 2007 and 2008 in the United States, and the European sovereign debt crisis). The estimated regressions were used to indicate the direct effects of economic policy uncertainty on the return volatility of the stock in the four large Greek banks. Volatility is constructed based on intraday data, whereas four different estimators of volatility were used.
- ItemOpen AccessCapital structures of US market firms and its determinants during different macroeconomic states and various leverage levels
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)(2023-10-23) Σαλάτας, Ηλίας; Salatas, IliasThis thesis investigates multiple factors under the framework of Trade-off theory capital structure theory, initially at a theoretical but mainly at an empirical level under the context of an innovative econometric model. It is an undeniable fact that capital structure is a prerequisite objective for every successful firm and an indication of the effectiveness of administration. This challenge hinders to develop when the economic cycles and financial status are shifting rapidly. In this study, we initially investigate the behavioral variety of firm adjustment speed to targeted debt levels and the capital structure determinants that provide acceleration or brake with special emphasis on different leverage levels and macroeconomic states under the prism of debt maturity distention. Specifically, we examine how these relationships are affected in a span of 44 years, for more than 17.000 United States of America based firms. Moreover, we apply an innovative quantile regression partial adjustment model that enables the investigation of the entire conditional distribution of the response variable. Our findings indicate slow adjustment speed to the desired debt ratio levels and that the lagged debt ratio is the main capital structure determinant regardless the debt maturity distinction (short-debt, long-term debt, total debt). In addition, low leveraged firms tent to adjust faster to targeted debt levels than mid and high leveraged ones not only on normal periods but also over crisis periods although with a slower pace. The investigational approach also reveals that firms are not impacted equally from economic crisis. Finally, is verified that companies exposed to certain factors studied here and with firm characteristics like those of the sample we used in our study, are affected to a different degree depending on the level of leverage and depending on the maturity of the debt. The internal and external corporate factors whose effect is studied over the capital structure are the ratios of long-term, short-term and total debt to capital respectively (long-term debt/total assets, short-debt/total assets, total-debt/total assets), the liquidity to capital (cash/total assets), profitability, size of the business, growth, asset consolidation (tangibility) and external factors such as inflation and the nominal interest rate lending interest.
- ItemOpen AccessData envelopment analysis models for performance measurement and management of public policy implementation : evidence from delivery of a social economic development program
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Πέττας, Νικόλαος; Γιαννίκος, Ιωάννης; Γιαννίκος, Ιωάννης; Ζαχαράτος, Γεράσιμος; Τσάντας, Νικόλαος; Μαρούδας, Λεωνίδας; Ανδρουλάκης, Γεώργιος; Κουνέτας, Κωνσταντίνος; Τσαγκανός, Αθανάσιος; Pettas, NikolaosPublic Administration is facing tremendous challenges and it is at the center of political, economic and social developments. In Greece Public Administration presents serious problems, the analysis and elimination of which requires the adoption and implementation of new organizational structures, administrative practices and governance processes. Performance measurement is a significant driver of the use of performance information in management, in particular for decision-making on the delivery of public spending programs. There is increasing recognition that performance evaluation of public spending programs should emphasize on their implementation rather than focus solely on their outcomes. This study for the first time presents a framework for comparing the delivery or administrative efficiency of public spending programs, based on a novel application of a quantitative operational technique, Data Envelopment Analysis (DEA). It is focused on the European Union context and precisely in the implementation of Greek LEADER operational program. Research on performance in public spending programs is focused mainly on their effects on target groups and areas. To the best of our knowledge, there is no a study quantifying the delivery efficiency of a public spending program. This research contributes to improve the current methods of public program delivery assessment by exploring new methodologies, based on a frontier technique, which can effectively provide enhanced managerial information to program implementers and managing authorities and recommendations to ministries towards better public policy implementation. From the alternative frontier methods available, in this study it was chosen to explore in detail the use of Data Envelopment Analysis due to the greater flexibility to incorporate the multidimensional nature of the socioeconomic development policy, the use of minimal assumptions on the shape of the best practice frontier and because it has the advantage of allowing comparisons with the best observed performance by constructing a best practice frontier based on empirical input and output data. Moreover, we apply new nonparametric estimation procedures based on DEA to estimate technical change, relative efficiency change, and productivity change in program delivery as well as the components of efficiency change. In order to evaluate the impact of contextual variables on program productivity we developed a two-stage method that uses DEA in the first stage and OLS regression in the second stage. Through the use of linear programming, DEA constructs a frontier from a subset of efficient best practice program implementers and identifies which delivery units are inefficient compared to it. Output oriented CCR and BBC DEA models provide technical efficiency scores which give the magnitude of the inefficiencies present in relation to the distance of the inefficient units to the frontier enveloping them. For each inefficient implementer, DEA gives efficient resource savings and output increases and a reference set or peer group of efficient implementers, which is most similar to it in their mix of services and resources and constitutes a realistic term of comparison. Strong evidence of operational and scale inefficiencies in mid-term of program implementation is found, suggesting that the delivery system suffers significant absorption problems due to inefficiencies in program administration. These findings emphasize the need to improve program administrative capacities in Greece and suggest adjustments in a number of program implementers charged with the delivery of rural development policy. Furthermore, the study finds significant time improvements in productivity of program delivery. The results of productivity growth and changes in its components from the pre- to post- mid-term implementation period indicate that program implementers experienced a statistically significant increase on average productivity between the two periods. In addition, it is found that the productivity gain may be primarily attributed to a change in relative efficiency rather than to technical progress. Evidence from the comparison of efficiency scores across the regions indicates that location of implementers and their programs might have influenced their delivery performance. We also confirmed the presence of economies of scale in program administration which might be a justification for selecting bigger target areas, population and programs, since economies of scale may require a larger program area than it is possible within a particular small local area. Finally, with respect to factors affecting program delivery productivity, both sizes of delivery mechanism and program budget are significant variables which have implications on program productivity. This infers that local program implementers with average administration resources and larger program budgets have higher likelihood of being efficient. Overall, the results of this study illustrate that DEA, in contrast to traditional program performance measures, is an insightful tool in revealing administrative inefficiencies in program delivery by capturing the operational and scale components of performance while taking into account the complex mix of tasks and interventions carried out by its operators and also allowing for innovation and locally designed solutions able to meet community’ needs. Moreover, the proposed technique may be easily integrated into a program evaluation exercise and may be utilized as a knowledge tool to support rational management decision-making and program improvement.
- ItemOpen AccessE-government : privacy preserving authentication technologies and benefits for the state and the citizen
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Ναστούλη, Δήμητρα; Nastouli, DimitraThis dissertation focuses on privacy as well as the technologies that can enhance privacy in the context of applications that are part of a broader framework for developing innovative e-Government services aimed at attracting citizens’ confidence. In order to eliminate the negative elements of today’s identification methods that often lead to the disclosure of more information about the individual than it is necessary, a new line of research has been developed in recent years to create digital certificates based on the disclosure of selected user identity elements. This research has led to the creation of the Attribute Based Credentials (ABCs) which are digital certificates that allow their holders to disclose, selectively and under their own control, only the information required by the service they wish to use, without giving full details of their complete identity, thus protecting the identity elements of the users and their privacy. These certificates can, therefore, be the cornerstone of reliable, trustworthy, and at the same time secure applications in which those involved (people and devices) can be partially identified without compromising their privacy. Within this context, in this dissertation, we propose a new business model for innovative e-Government applications (without limiting the use of the model in this field) based on Collective Intelligence, focusing on privacy technologies such as the ABCs. The goal is to describe a business model for supporting applications for smart cities and services that people can trust and, also, participate in their operation. More specifically, in the context of this model, privacy preserving techniques are described to connect multiple computing devices and people aiming at the massive gathering of environmental parameters as well as their distributed storage and processing on people’s devices, in a way that respects the privacy of the participants (devices and people alike). Participants help, using the sensors on their mobile devices, in data collection related to their ambient environment (e.g. temperature) or their behavior (e.g. movement). In this way, applications can draw useful information after proper processing of the sent information. Also, in the framework of this dissertation, a new mathematical model is proposed for partial identity disclosure certificates and ABCs in particular that allows the formulation of quantitative privacy level evaluation criteria that can assess whether it is safe to disclose a subset of a person’s identity elements without (or with minimal) privacy loss. These criteria are based on the Bayes theory and conditional probabilities, leading to an approach of evaluating the privacy risk of revealing a set of identity elements to a service. Finally, the results of a survey are presented which aims at highlighting the issues and concerns inherent in the use of electronic identification methods in the Public Sector. The survey, also, reveals how these problems are addressed by public officials in view of the new ABCs technologies. The aim of this research is to strengthen the trust of Public Officials in the applications they use in their daily tasks to support the eGovernment vision.
- ItemOpen AccessEssays on measuring systemic risk
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Konstantatos, Christoforos; Τσαγκανός, Αθανάσιος; Τσαγκανός, Αθανάσιος; Συριόπουλος, Κωνσταντίνος; Γαλαριώτης, Αιμίλιος; Γεωργόπουλος, Αντώνιος; Ανδρουλάκης, Γεώργιος; Πενταράκη, Κωνσταντίνα; Αγγελόπουλος, Ελευθέριος; Κωνσταντάτος, ΧριστόφοροςThe present dissertation explores various approaches of measuring the systemic risk, identifying the systemic important banking institutions and exploring extreme equity price movements of euro area banking institutions. It consists three chapters focusing on U.S. and euro area banking institutions. Chapter 2 investigates the contribution and the exposure of banking institutions to systemic risk and compares the systemic measures named (i) Delta Conditional Value at Risk, (ii) Marginal Expected Shortfall and (iii) Systemic RISK. The results indicate that the euro area banking institutions impose the highest risk in financial system (contribution to systemic risk). In addition, they are the most vulnerable banking institution in case of a crisis. Moreover, the banking institutions with the highest expected losses in case of an extreme event are mainly US banking institutions. Chapter 3 examines the cross-Atlantic risk exposures by using Conditional Value at Risk measure to capture the evolution of tail risk dependence. Specifically, Chapter 3 investigates the systemic risk between the US and European Monetary Union banking institutions. The results highlight that the two largest German banking institutions are among the most vulnerable euro area banking institutions to risk exposures derived from US banking institutions which in turn are highly exposed to the three largest French banking institutions. Chapter 4 investigates the tail dependence structure of the twenty-four largest banking institutions in the euro area before and after the Lehman Brothers collapse. The results indicate that in the post-crisis sub-period the level of correlation of negative return exceedances increases substantially amongst banking institutions in the euro area core. However, among the countries which receive rescue packages, the largest banking institutions in Greece and Ireland decline the extreme correlation with almost all the rest of the largest banking institutions in the euro area.
- ItemOpen AccessForecasting the spreads of bond yields using the credit default swaps during the financial crisis
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Δημητρόπουλος, Βασίλειος; Τσαγκανός, Αθανάσιος; Συριόπουλος, Κωνσταντίνος; Ευγενίδης, Αναστάσιος; Γεωργόπουλος, Αντώνιος; Παπαδάμου, Στέφανος; Πενταράκη, Κωνσταντίνα; Τσαγκανός, Αθανάσιος; Dimitropoulos, VasileiosThis thesis copes with the main factors of credit risk and its relation to investors’ expectations, as well as the possible existence of investors' expectations regarding the transmission channel of the ECB's contractual and unconventional monetary position. In introduction, we state the major procedures that marked the recent period of turmoil in the global financial markets. The second chapter discusses the credit risk valuation to study the determinants of CDS exchange rate developments for euro area countries and the possible transmission impacts of peripheral countries to core countries after the recent recession in the EU. To examine this, it is applied a model with the traditional advantages of VAR modelling and the benefits of a panel data approach which is the PVAR (Panel Vector Autoregressive model). Besides that, the analysis uses factors that proxy determinants for behavioral as well as proxy determinants for financial and global market spread. The major results shows that, after the financial crisis through different countries and periods, the CDS variable determinants presents neither stable nor uniform. For example, as we go through the period 2012 to 2018, the impact of the slope of term structure in the sovereign CDS spread variance is increasing for the peripheral countries (Greece, Ireland, Italy, Portugal and Spain) and for the core countries is decreasing (Austria, Belgium, France, Germany and the Netherlands). In addition, we indicate that the impacts of transmission after the recent financial crisis run from Portugal and Italy economies to the core countries, since effects from Greece, Spain and Ireland are of minor importance. Italy, being one of the largest economy in EU could potential disrupt the Eurozone area; although the probability of financial difficulty is perceived by the markets as being relatively smaller, based on sovereign CDS spreadsThe third chapter, for the first time, copes with the proof of the monetary policy shocks of ECB about the financial expectations in Eurozone area after the financial crisis in EU. The results present that the unconventional monetary policy of ECB has a positive impact on sentiment and expectations. In addition, the outcomes from the analysis indicate that the ECB's conventional monetary policy takes a positive and important impact on EU sentiment and expectations for the peripheral countries, since the conventional monetary policy of ECB contributes significantly to variance of peripheral European countries, and more specific after the US and Euro area economic crisis. It should be noticed that, after the Eurozone crisis, the conventional monetary policy stance of ECB seems to be the most significant net sender of effects to the peripheral countries of the EU, since for the core countries is the second significant receiver. The ESI is the following in significance net sender of impacts of the system for the core countries. The findings end up with the significance of conventional monetary policy in identifying financial expectations.
- ItemOpen AccessH αποτίμηση του κρατικού χρέους στις αγορές ομολόγων : η πραγματικότητα των περιφερειών απέναντι στο όραμα της χρηματοοικονομικής ολοκλήρωσης στην Ευρωζώνη
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Σβίγγου, Αργυρώ; Tσαγκανός, Αθανάσιος; Τσαγκανός, Αθανάσιος; Φίλιππας, Διονύσιος; Συριόπουλος, Κωνσταντίνος; Γεωργόπουλος, Αντώνης; Ανδρουλάκης, Γεώργιος; Πενταράκη, Κωνσταντίνα; Αγγελόπουλος, Ελευθέριος; Svingou, ArgyroΗ παρούσα διδακτορική διατριβή διερευνά σε θεωρητικό και εμπειρικό επίπεδο το βαθμό που οι αγορές κρατικών ομολόγων της Ευρωζώνης είναι χρηματοοικονομικά ολοκληρωμένες. Μέσα από την διερεύνηση πιθανών αλληλεπιδράσεων μεταξύ των σπρέντ των κρατικών ομολόγων και την αναζήτηση κοινών συνιστωσών που μπορεί να επηρεάζουν την πορεία τους, για την περίοδο 2003-2018, δείχνουμε ότι η χρηματοοικονομική ολοκλήρωση συνεχίζει να αποτελεί ζητούμενο.
- ItemOpen AccessH κοινωνική επιχειρηματικότητα στην Ελλάδα : μια εμπειρική διερεύνηση της οργανωσιακής συμπεριφοράς και της απόδοσης των κοινωνικών επιχειρηματιών
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)(2023-09-26) Σωτηροπούλου, Αικατερίνη; Sotiropoulou, AikateriniH κοινωνική επιχειρηματικότητα αναγνωρίζεται ως ένας σημαντικός μηχανισμός για την δημιουργία καινοτόμων, ουσιαστικών και βιώσιμων λύσεων σε κοινωνικά προβλήματα. Οι κοινωνικοί επιχειρηματίες αποτελούν αναπόσπαστο μέρος των κοινωνικών επιχειρήσεων, καθότι είναι τα άτομα που ιδρύουν και διαχειρίζονται τους οργανισμούς αυτούς, και επιδιώκουν τη δημιουργία κοινωνικής αξίας και την αντιμετώπιση επίκαιρων κοινωνικών προκλήσεων. Επομένως καθίσταται σημαντική η διερεύνηση των χαρακτηριστικών και των κινήτρων που καθορίζουν τις ενέργειες και συμπεριφορές τους, οι οποίες συνδέονται έμμεσα με την αποτελεσματικότητα των κοινωνικών εγχειρημάτων. Ο σκοπός της παρούσας διατριβής είναι η χαρτογράφηση των προσωπικών αξιών των κοινωνικών επιχειρηματιών, και η συστηματική μελέτη του μηχανισμού συμπεριφοράς τους εντός των κοινωνικών επιχειρήσεων που συμβάλει σε υψηλότερες ατομικές αποδόσεις. Η μεθοδολογική προσέγγιση που ακολουθείται είναι ποσοτική, και το δείγμα της επισκόπησης αποτελείται από 226 κοινωνικούς επιχειρηματίες, ιδρυτές ισάριθμων κοινωνικών συνεταιριστικών επιχειρήσεων (Κοιν.Σ.Επ.) στην Ελλάδα. Αρχικά διενεργείται περιγραφική ανάλυση σχετικά με το κοινωνικό-δημογραφικό προφίλ, τα χαρακτηριστικά ενασχόλησης των κοινωνικών επιχειρηματιών στις κοινωνικές επιχειρήσεις καθώς και της αποτύπωσης των κυρίαρχων προσωπικών αξιών τους βάσει της θεωρίας των βασικών αξιών του Schwartz. Τα αποτελέσματα δείχνουν ότι οι κοινωνικοί επιχειρηματίες στην Ελλάδα είναι μέσης ηλικίας, υψηλού μορφωτικού επιπέδου, και η κοινωνική επιχειρηματικότητα, για ομάδα εξ αυτών, αποτελεί εργαλείο για την είσοδό τους στην αγορά εργασίας. Οι κυρίαρχες αξίες που υιοθετούν συχνότερα είναι η παγκοσμιότητα, η φιλανθρωπία και ο αυτοπροσδιορισμός. Τα αποτελέσματα της επιβεβαιωτικής παραγοντικής ανάλυσης (Confirmatory Factor Analysis) του μοντέλου των προσωπικών αξιών συγκλίνουν ότι οι πιο σημαντικές ομάδες αξιών για τους κοινωνικούς επιχειρηματίες είναι η Υπέρβαση του Εαυτού και η Δεκτικότητα στις Αλλαγές. Με βάση τις αξίες, η συνεπακόλουθη ανάλυση συστάδων (Cluster Analysis) αναδεικνύει τέσσερις διαφορετικούς τύπους κοινωνικών επιχειρηματιών που φέρουν τους ακόλουθους τίτλους: Συντηρητικοί, Συμβατικοί, Συνετοί και Επιτηδευμένοι. Η διατριβή εμβαθύνει επίσης στο μίκρο-περιβάλλον των κοινωνικών επιχειρήσεων, στηριζόμενη στις βασικές υποθέσεις της θεωρίας της κοινωνικής ταυτότητας και διερευνά 12 επιμέρους ερευνητικές υποθέσεις. Πιο συγκεκριμένα μελετά την επίδραση και την αλληλεπίδραση της Συναισθηματικής Δέσμευσης και της Εργασιακής Δέσμευσης στην Ατομική Απόδοση των κοινωνικών επιχειρηματιών, καθώς και τον ρυθμιστικό ρόλο (moderation effect) των προσωπικών αξιών στις παραπάνω μεταβλητές αλλά και στις μεταξύ τους σχέσεις. Για το σκοπό αυτό, σχεδιάζεται και ελέγχεται ένα αρχικό μοντέλο δομικών εξισώσεων (Structural Equation Model-SEM) για την εκτίμηση των σχέσεων μεταξύ των μεταβλητών της συναισθηματικής δέσμευσης, της εργασιακής δέσμευσης και της ατομικής απόδοσης, καθώς και τέσσερα ακόμη δομικά μοντέλα τα οποία εστιάζουν, με τη μέθοδο των μετρήσεων πολλαπλών ομάδων (multigroup moderations), στο ρυθμιστικό ρόλο των προσωπικών αξιών στις παραπάνω σχέσεις των τριών μεταβλητών. Τα αποτελέσματα φανερώνουν ότι η Συναισθηματική Δέσμευση και η Εργασιακή Δέσμευση αποτελούν δύο μεταβλητές με ισχυρή θετική επίδραση στην Ατομική Απόδοση των κοινωνικών επιχειρηματιών. Επίσης, η ομάδα αξιών της Υπέρβασης του Εαυτού επιδρά στην διαμόρφωση υψηλότερης συναισθηματικής δέσμευσης, εργασιακής δέσμευσης και ατομικής απόδοσης και καθιστά ισχυρότερη την σχέση μεταξύ συναισθηματικής δέσμευσης και εργασιακής δέσμευσης. Η ομάδα αξιών της Δεκτικότητας στις Αλλαγές επιδρά στην διαμόρφωση υψηλότερης συναισθηματικής δέσμευσης και εργασιακής δέσμευσης και καθιστά ισχυρότερη την επίδραση της συναισθηματικής δέσμευσης στην εργασιακή δέσμευση. Ενώ η ομάδα αξιών του Συντηρητισμού συμβάλει σε υψηλότερη εργασιακή δέσμευση και ατομική απόδοση και καθιστά πιο ισχυρή την επίδραση της εργασιακής δέσμευσης στην ατομική απόδοση. Η διατριβή συμβάλει στην αντιμετώπιση σημαντικών ερευνητικών κενών που εντοπίζονται στην διεθνή και ελληνική βιβλιογραφία αναφορικά με την αξιοσημείωτη ετερογένεια που παρατηρείται στους κοινωνικούς επιχειρηματίες, ως προς τις προσωπικές αξίες που υιοθετούν. Επίσης, η παρούσα μελέτη συνεισφέρει νέα ερευνητικά ευρήματα στο πεδίο της οργανωσιακής συμπεριφοράς των κοινωνικών επιχειρηματιών και ειδικότερα ως προς τις μεταβλητές συναισθηματική και εργασιακή δέσμευση και ατομική απόδοση. Τέλος, η διατριβή εμβαθύνει στο πως οι προσωπικές αξίες διαμορφώνουν το βαθμό της εργασιακής και συναισθηματικής δέσμευσης, και συμβάλλουν στις ατομικές αποδόσεις των επιχειρηματιών, στο πεδίο της κοινωνικής επιχειρηματικότητας.
- ItemOpen AccessIncorporating decision-makers’ perspectives into DEA models by means of weight restrictions
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)(2023) Γκουβίτσος, Ιωάννης; Gkouvitso, IoannisThis thesis discusses an important issue in the field of Operational Research, particularly in the efficiency assessment of DMUs by means of the Data Envelopment Analysis method. In fact, we investigate the field of DEA weight restrictions and their use as a means of incorporating managerial decisions, priorities, or decision makers’ perceptions into the relevant DEA models. The thesis consists of two parts, each of which explores the use of weight restrictions in a different context, with the objective to provide decision-makers with flexibility regarding the determination of DEA weights. The first part proposes a new approach that performs a complete ranking of decision-making units (DMUs), by employing Data Envelopment Analysis (DEA) models with virtual weight restrictions. It is a multi-stage process that employs the super-efficiency DEA model (AP Model) at each stage of the process. In each stage, the virtual weight bounds could be different and are obtained by means of the MACBETH methodology. Our approach has been applied in a real-life application, where three decision-makers need to perform a complete ranking of 33 Greek general hospitals. The empirical results indicate that the proposed multi-stage ranking approach increases the discrimination power of the conventional super-efficiency DEA model and provides an improved DMUs ranking. The importance of such an improvement is more prominent in situations where a decision related to funds or other resource allocation should be made. Thus, the proposed approach not only contributes to the relevant literature but also is quite important from a decision-making perspective, as it is the first (to the best of our knowledge) allowing decision-makers to adjust the DEA weights at each stage of the ranking process. The second part proposes the incorporation of fuzzy numbers into the production trade-off weight restrictions approach. The key idea of the discussed approach is that in real-life DEA applications, existing production trade-offs among inputs and/or outputs may be extremely difficult to express with crisp numbers. The proposed approach allows decision-makers to restrict the weights of DEA models, by expressing complex production trade-offs in fuzzy terms. With this approach, the obtained efficiency scores remain meaningful from a production perspective and more compatible with real-life applications that often involve ambiguity or uncertainty. Based on the fuzzification of production trade-offs, we introduce DEA models that consider the ambiguity inherent in realistic processes and determine appropriate efficiency scores and targets for the DMUs.
- ItemOpen AccessInnovation management and firms' performance : the role of business strategy, organizational capabilities and external environment
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)(2014-02-20) Μαμμασής, Κωνσταντίνος; Αναστασόπουλος, Γεώργιος; Αναστασόπουλος, Γεώργιος; Πεχλιβανίδης, Παντελής; Συριόπουλος, Κωνσταντίνος; Μαρούδας, Λεωνίδας; Γιαννίκος, Ιωάννης; Πολυχρονίου, Παναγιώτης; Κωστόπουλος, Κωνσταντίνος; Mammassis, ConstantinosIn the modern highly competitive business environments innovation research has flourished as the need of organizations to develop new products, to compete intensively and to perform their tasks adequately has become vital (Brown & Eisenhardt, 1995; Damanpour, 1991). This continuous change leads firms to confront with the tension of exploring new opportunities or exploiting current competencies (Floyd & Lane, 2000; Lavie, Stettner, & Tushman, 2010). March’s (1991) “ambidexterity” premise refers to the simultaneous pursuit of these contrasting activities (exploration and exploitation). Specifically, firms seek to adjust to the turbulent environmental conditions through exploring new ideas, products and/or services while simultaneously developing their existing products, markets and competences (Benner & Tushman, 2003; Jansen, Van Den Bosch, & Volberda, 2006). Several literatures have increasingly argued about the antecedents of exploration and exploitation and their impact to firms’ ambidexterity as well as the relationship between ambidexterity and firms’ financial performance (He & Wong, 2004; Jansen, Volberda, & Van Den Bosch, 2005a). This doctoral study copes with the antecedents of firms’ ambidextrous orientation and the firm-level ambidexterity-financial performance relationship. Through the use of hierarchical regression modeling, the results of the empirical research at a sample of 133 top performing Greek companies show that: 1) top managers’ creative self-efficacy positively affects firms’ ambidextrous orientation, 2) top managers’ learning goal orientation positively impacts firms’ ambidextrous orientation, 3) top managers’ performance goal orientation negatively influences firms’ ambidextrous orientation, 4) firms’ external knowledge flows positively affect firms’ ambidextrous orientation, 5) firms’ innovation & flexibility climate positively impacts firms’ ambidextrous orientation, 6) firms’ social capital is not associated with firms’ ambidextrous orientation, 7) firms’ organizational capital positively influences firms’ ambidextrous orientation, 8) firms’ participative decision making positively affects firms’ ambidextrous orientation, 9) the complementary effect of the simultaneous pursuit of a differentiation and a low-cost strategy negatively impacts firms’ ambidextrous orientation, 10) firms’ ambidextrous orientation is positively related to firms’ financial performance and that, 11) Firm size moderates the relationship between firms’ ambidextrous innovation orientation and its subsequent financial performance in such a way that this positive effect is increased as size increases. Overall, these findings offer important contributions to organizational ambidexterity literature, by indicating new antecedents of firms’ ambidexterity and a positive relationship of ambidexterity and firms’ financial performance.
- ItemOpen AccessLong-run causal effects of public investments : economic growth and the provision of schooling. Greece 1960-2015. Parametric and nonparametric approach
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Κασάπη, Σοφία; Συριόπουλος, Κωνσταντίνος; Αστερίου, Δημήτριος; Σαμιτάς, Αριστείδης; Kassapi, SophiaThe question addressed here has been whether public investments in the provision of statutory schooling promote economic growth, in terms of GDP per capita, for the case of Greece. This dissertation joins a vibrant discussion of whether public investments compose the necessary pedestal for the private investments to increase, whenever they are targeted towards new infrastructures, providing better market conditions for all business sectors. This study adopts the standard parametric econometric toolbox developed upon Granger causality methodology (1969) and goes one step forward in the direction of the nonparametric analysis. The non-parametric test used in this hypothesis testing is the Diks and Panchenko (2006) modified test statistic, initially proposed by Hiemstra and Jones (1994). The original HJ is not used due to its over-rejection problems. Consequently, the Diks and Wolski (2013) “data sharpening” extension to the DP nonparametric Granger causality test is being applied, in order to address the consistency issues of the basic DP test statistics in multivariate settings, regarding the kernel estimation bias. By applying nonlinear nonparametric Granger C codes on VAR and E-GARCH residuals, annual time series which were converted into quarterly data through cubic spline interpolation method. For the analysis of the data, MATLAB functions and C Codes were developed and used. The results taken are consistent with more general findings on the impact of public spending on economic growth (ECB, 2008), and do not justify these levels of public investment in schooling, in terms of growth. The promotion of free public schooling does not promote economic growth for the country in most levels, especially higher education and middle school, while other intermediate causal effects revealed show us an even more complex situation of interdependencies and synergies. Even according to the European Central Bank (ECB, 2005), public investment in human capital and R&D can be a main growth element, under certain conditions. It seems like this expansion in years of schooling alone, was not the only measure needed to provide for better economic conditions. The controversy here implies the importance of cognitive skills in promoting economic growth (Hanushek, E., 2013), and the need to shift our focus on quality for both basic skills and high achievers, either to alleviate poverty, or raise their level of income respectively. Data were collected from the Greek Statistics Bureau (ELSTAT) and AMECO for the 1960-2015 time. Unfortunately, the data collection process dealt with important data limitations. The lack of consistent and comparable data, and the unwillingness of the officials to cooperate led this study to shrink from a panel data analysis that was previously intended to a time-series one. Hopefully in the near future, another study will provide for more qualitative elements on the “uncertain role of human capital on growth”. Thankfully, the analysis gained robustness from the methods employed, and provided with a clear picture on public spending for schooling in the beleaguered Greek economy.
- ItemOpen AccessA mathematical model for financial innovation : empirical evidence from financial markets
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)(2011-10-03T06:15:29Z) Φίλιππας, Διονύσιος; Συριόπουλος, Κωνσταντίνος; Ανδρουλάκης, Γεώργιος; Γιαννακόπουλος, Αθανάσιος; Παυλίδης, Γεώργιος; Αστερίου, Δημήτριος; Γιαννίκος, Ιωάννης; Pilbeam, Keith; Συριόπουλος, Κωνσταντίνος; Filippas, DionysiosFinancial innovation is an important research topic modern economics. Financial innovation is an ongoing process where new financial products, services and procedures are created and it concerns important financial factors such as the regulatory restrictions, the relationship between financial innovation and the functionality of financial markets, the inefficiency of markets promoted by globalization and unexpected changes of economic status and financial intermediary. The previous literature that deals with financial innovation is relatively constrained compared to the significance of the issue, which is a surprise considering the relative abundance of such research on other sectors of finance and economics. The consequences of financial innovations concern the functional framework of capital markets, the microeconomic and the macroeconomic functional frameworks. This thesis studies the influence of diffusion of financial innovation to market participants’ frictions and their values, through a theoretical, mathematical and empirical framework. We derive a novel measure of the influence of financial innovation to the market participants based on their correlation friction patterns. The main objective is to highlight a number of aspects and dimensions of this field. In particularly, we aim to present: i) the theoretical framework on the role of financial innovation at the financial structure (the fundamental generating root causes and the effects on the function of financial markets, etc), and ii) the parameterization of the influence of financial innovation to market participants through a mathematical and econometric framework based on the participants’ minimum need for change, the diffusion rate and time parameter. We undertake an extensive empirical analysis about the influence of introduction and diffusion of a financial innovation to market participants. The findings lead us to the conclusion that the parametric function, which is followed in order to show the influence of diffusion of financial innovation, has a statistically significant impact on returns and volatility of financial and economic indices.
- ItemOpen AccessModeling extreme events in financial markets : theοry and applicatiοns
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Γκίλλας, Κωνσταντίνος; Συριόπουλος, Κωνσταντίνος; Τσερκέζος, Δίκαιος; Τσαγκανός, Αθανάσιος; Ανδρουλάκης, Γεώργιος; Γιαννίκος, Ιωάννης; Παπαδάμου, Στέφανος; Φίλιππας, Διονύσιος; Gkillas, KonstantinosIn this thesis, we emplοy univariate and multivariate extreme value theοry in οrder tο investigate the behaviοur οf extremes during variοus bοοms and crashes in financial markets. We select sοme οf the mοst impοrtant periοds in financial markets, such as the glοbal financial crisis and the Eurοpean debt crisis. As for the univariate extreme value theory, we prοpοse a parametric bοοtstrap bias-corrected apprοach tο test the reliability οf risk measures and financial risk trends in the Athens stοck exchange (ASE) befοre and after capital cοntrοls οn banking οutflοw funds. We also prοpοse a nοn-parametric bias-cοrrected apprοach to investigate the structure of financial risk in UK financial markets during the glοbal financial crisis. As for the multivariate extreme value theory, we investigate the effect οf restrictiοns οn transactiοns, due tο capital cοntrοls in ASE, οn tail dependence structure οf return exceedances and transactiοn vοlumes using bivariate extreme value theοry. We prοpοse a parametric bοοtstrap bias-cοrrected apprοach tο οbtain mοre accurate results, cοmparing dissimilarly-sized samples. We alsο apply the previous procedure tο investigate the tail dependence structure οf the returns οf the ten largest cryptοcurrencies in a pairwise cοmparisοn, estimating an extreme cοrrelatiοn cοefficient. Finally, we prοpοse an asymmetric exceedance-time mοdel with οptimal threshοlds, which allοws us tο examine the impact οf extreme dοwnside and upside extreme events and tο determine hοw the duratiοn between past and present extreme shοcks affects the dependent variable. We apply οur mοdel tο the exchange and equity markets tο better understand the interactiοns between these twο markets during extremely vοlatile periοds.
- ItemOpen AccessRelevance and knowledge dynamics for intelligent agents
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Αραβανής, Θεοφάνης; Σταματίου, Ιωάννης; Σταματίου, Ιωάννης; Ανδρουλάκης, Γεώργιος; Ροντογιάννης, Παναγιώτης; Πέππας, Παύλος; Καραζέρης, Παναγής; Χατζηλυγερούδης, Ιωάννης; Δημητρακόπουλος, Κωνσταντίνος; Aravanis, TheofanisThis doctoral dissertation studies contemporary issues of relevance and knowledge dynamics for intelligent agents. The research area that models knowledge in flux is that of Belief Revision (or Belief Change). In Belief Revision, as in many areas of Artificial Intelligence, relevance constitutes a crucial notion, both conceptually and computationally. The contributions of the dissertation to the aforementioned subjects are in the form of high-quality formal results and practical implementations oriented towards real-world problems. Belief Revision is a young field of research that lies in the broader context of Knowledge Representation and Reasoning. The milestone of Belief Revision is a general and versatile formal framework introduced by Alchourron, Gardenfors and Makinson, known as the AGM paradigm (after the initials of its founders), which is, to this date, the dominant within the field. The AGM paradigm captures both axiomatically and constructively the process of rational belief revision. Two main shortcomings of the AGM paradigm, as originally proposed, are its lack of any guidelines for relevance-sensitive and iterated belief revision. A major part of this dissertation is devoted to the establishment of important results concerning these two central sub-areas of Belief Revision. In particular, we study Parikh's relevance-sensitive axiom, as well as the most influential work addressing the problem of iterated belief revision, i.e., Darwiche and Pearl's approach. In a more applied direction, several concrete "off the self" revision functions (operators), implementing the process of belief revision, have been proposed. In this work, we study a new and important proper subclass of AGM revision functions, called Parametrized Difference revision operators (or PD operators), which are natural generalizations of the well-known and intuitive Dalal's revision operator. PD operators bring us a step closer to the development of a successful AGM belief-revision system for real-world applications, due to their favourable properties, such as the low representational and computational cost, and the high expressivity. Lastly, in this dissertation, a preliminary knowledge-based system capable of (formally) representing and reasoning about legal knowledge is developed. The work is implemented by means of the powerful and contemporary Answer Set Programming framework. The system has a plethora of extensions, and a variety of nice features (such as sufficient and reliable representation of the legal knowledge, handling non-monotonicity and exceptions, appropriate expressive power) that, in essence, reflect the nature of the Law. The overall approach constitutes an enhancing of the bond between Artificial Intelligence and Legal Science.
- ItemOpen AccessStrategic management of hotel multinationals : environment, management, performance
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)(2013-02-28) Γιαννούκου, Ιωάννα; Αναστασόπουλος, Γεώργιος; Γιαννίκος, Ιωάννης; Πεχλιβανίδης, Παντελής; Γεωργόπουλος, Αντώνιος; Γκίκας, Δημήτριος; Μαρούδας, Λεωνίδας; Λαγός, Δημήτριος; Αναστασόπουλος, Γεώργιος; Giannoukou, IoannaTraditionally, tourism was placed second as a priority in the agenda of investors, policy makers, and academics. Nowadays, a significant reappraisal of its role in socioeconomic development is taking place, which values tourism as a source for earning export revenues, generating large numbers of jobs, promoting economic growth and a more services-oriented economy not only in developing but also in developed countries (UNCTAD, 2007). According to World Tourism Organization (WTO), the European Union (EU) numbered six Member States among the top 10 countries in the world welcoming the largest number of international tourist arrivals. Within the EU, receipts from international tourism in 2008 were highest in Spain, France, and Italy, followed by Greece and Portugal Previous studies have attempted to explain destination and/or firm strategic positions by focusing on (mostly demand side factors) prices, exchange rates, qualitative and other institutional factors. Supply side factors and in particular company strategy contact and performance have not been taking explicitly into consideration. However, important pioneer research has been done regarding the globalization of the service sector and the hotel industry (Dunning and McQueen 1981, 1982; Boddewyn et al., 1986; Li and Guisinger, 1992; Dunning and Kundu, 1995; Constractor and Kundu, 1995). The topic under scrutiny is, therefore, to investigate whether MNEs operating in Greece, France, Spain, Portugal and Italy perform differently than domestically owned firms. In particular, we seek to identify the relevant factors that may explain the performance implications of foreign ownership for a large cross section of firms in Greek, French, Spanish, Portugues and Italian industries, controlling for a number of factors affecting firms’ performance. A closely related topic is to examine whether MNEs perform well per se, or their relative superior performance is a consequence of the detrimental effect they may exercise on domestic profitability. Additionally, we will try to determine the relative importance of the firm and destination effects using a multilevel approach and hierarchical linear models.
- ItemOpen AccessStudies on the behaviour and implications of corporate profitability on future performance and risk
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Λουκόπουλος, Παναγιώτης; Ανδρουλάκης, Γεώργιος; Ανδρουλάκης, Γεώργιος; Γεωργόπουλος, Αντώνιος; Κουμανάκος, Ευάγγελος; Συριόπουλος, Κώστας; Τσαγκανός, Αθανάσιος; Γουνόπουλος, Δημήτριος; Ιατρίδης, Γεώργιος; Loukopoulos, PanagiotisThe main aim of this thesis is to investigate the implications of asymmetries of accounting earnings on decision making. We distinguish such asymmetries in two main categories. The first considers the distributional properties of earning, and hence focuses on the potential consequences of the asymmetric distribution of earnings. The second refers to the time-series properties of earnings; thereby it focuses on the potential consequences of the asymmetric evolution of earnings (i.e., heterogeneous persistence or sustainability). To illustrate the economic importance of each of the above two issues, we examine each category of asymmetry within separate empirical contexts. Specifically, we investigate the implications of asymmetries in the distribution of earnings with regard to risk and its linkage with business strategies. On the other hand, for the examination of the implications of the asymmetric persistence in earnings, we adopt a more technical approach, and examine how the elements of the earnings generating contribute to asymmetric mean reversion patterns. Regarding the first type of asymmetry, we follow the strategy taxonomy of Miles and Snow from the organization literature. In this regard, we rely on decision and resource allocation patterns and categorize firms into Prospectors and Defenders. Prospectors are externally oriented organizations, embrace uncertainty, and grow rapidly as they concentrate their efforts in pioneering new products and exploiting market opportunities. At the opposite extreme, defenders are efficiency-oriented firms that operate on narrow and well-established markets. They compete on the basis of pricing policies and high quality products, prefer stability and consistent outcomes, and do not aggressively pursue new opportunities. The empirical analysis indicates that prospectors have lower profitability tendencies and greater occurrences of losses than defenders. Additionally, we show that prospectors are associated with higher total and downside earnings risk than defenders. Further analysis reveals that the higher (lower) exposure of prospectors to earnings downside (upside) risk is driven by the realized component rather than the accrual component. Specifically, we find that the conservative and efficient investment policy of defenders seems to pay off, as they have as they are exposed to lower downside cash flow risk and higher upside cash flow risk. On the other hand, the growth potential of prospectors is concentrated on the accrual component of earnings, as they have lower downside accrual risk and higher upside accruals risk than defenders.
- ItemOpen AccessTransmission of US monetary policy to the world economies. A time varying multi-country factor augmented vector autoregressive approach
Τμήμα Διοίκησης Επιχειρήσεων (ΔΔ)Ευγενίδης, Αναστάσιος; Συριόπουλος, Κωνσταντίνος; Σάμιτας, Αριστείδης; Φίλιππας, Διονύσιος; Μάλλιαρης, Αναστάσιος; Μάρκελλος, Ραφαήλ; Φίλιππας, Νικόλαος; Αστερίου, Δημήτριος; Evgenidis, AnastasiosIn this thesis, I examine the international transmission of US monetary policy shocks across euro area and Asian countries. For this purpose I use a time varying Factor Augmented VAR (FAVAR) model which I estimate by using Bayesian techniques. I first examine all the possible channels through which a policy shock is transmitted in each country. In general the transmission of the shock hides considerable heterogeneity across the countries. I find that trade balance is not a convincing channel in describing the pass through of policy shock in East Asia countries. Further investigation on the transmission in this region suggests that the wealth effects along with the world interest rate channel do explain the negative propagation of the US shock in in the GDP of Hong Kong, Philippines and Singapore. On the other hand, the exchange rate channel is suitable in explaining the GDP positive spillover effects in Korea and Japan. What is more, the foreign central banks of these two countries strongly respond to GDP increases -as a result of the US contractionary policy- by also increasing their short term rates. As concerns euro area, this endogenous response of central banks also holds for all the countries in the sample. Amongst the oher channels, the wealth effect through the exchange rate channel seems adequate to describe the transmission of the shock in European countries. For Germany and Italy the decline in lending and spending reveal the importance of the balance sheet channel in the shock transmission. Second, in the current thesis I investigate to what extent the transmission mechanism has changed through the years. I focus on two important worldwide phenomena, the effect of the globalization and the recent US financial crisis. I find that the impact of the shock in all economic variables in most of the non US countries has fallen under global integration. For the 2007 financial crisis, our results indicate that the majority of the countries in both regions witness an increase in the size of the shok to real activity, inflation and credit variables in the post crisis period.