This master thesis deals with a number of international processes in terms of geoeconomics. The main goal of this work is to research the position of dollar, ruble and petroleum in geoeconomic processes. At first goes the analysis of the current condition of the United States dollar, the assessment of exposure level of the system to other countries to establish the real role of the U.S. Federal Reserve. Then goes the analysis of the current status of Russian ruble and the Central Bank of Russian Federation. A large part of the work is devoted to petroleum as a basic raw material at present and its relations to U.S. dollar. At the end is the assessment of the U.S. dollar prospects in the 21 century and possible solutions, which will probably help to eliminate the negative consequences in case of using dollar as the dominant financial system in the world.

"Essays on Social Conflict and Reform" consists of four essays that study the political economy of policy reform. Social Conflict with Passive Groups examines conflicts over the distribution of income where groups that engage in appropriative activities as well as groups that are passive in this respect participate. Democratization, Rent Seeking, and Economic Transition uses a model of social conflict to determine the political and economic reform space and the economic performance in a society undergoing a transition from authoritarian rule to democracy and market economy. Constitutional Constraints and Redistributive Activities analyzes the effects of constitutional constraints against redistribution on the outcome of social conflicts. The Break-up of the Ruble Zone: Undertaking Monetary Reform while Building Democratic Institutions applies the theoretical findings of this dissertation to explain differences in monetary reform between countries in the former Soviet Union. / SITE, Stockholm Institute of Transition

Στόχος της παρούσης διπλωματικής εργασίας είναι να μελετηθεί η Ταχεία Διάχυση Αρνητικών Χρηματοοικονομικών Συμβάντων (financial contagion) όπως αυτή παρουσιάζεται στην βιβλιογραφία καθώς επίσης οι αιτίες, οι τρόποι διάχυσης και οι τρόποι μέτρησης της. Όσον αφορά στο εφαρμοσμένο κομμάτι της υπάρχουσας βιβλιογραφίας εξετάζεται το μέρος αυτής το οποίο αφορά στην εξέταση της Ταχείας Διάχυσης Αρνητικών Χρηματοοικονομικών Συμβάντων με μοντέλα περιορισμένης εξαρτημένης μεταβλητής. Γίνεται εκτενέστερη ανάλυση στο multinomial logit μοντέλο το οποίο φανερώνει την πιθανότητα εμφάνισης ενός ενδεχομένου σε σχέση με τις επεξηγηματικές μεταβλητές που επιλέγονται. Στα πλαίσια της εργασίας αυτής γίνεται και μια εμπειρική εφαρμογή ενός τέτοιου μοντέλου με δεδομένα που αφορούν την Ελληνική Χρηματιστηριακή Αγορά με σκοπό να δειχθεί αν οι χαμηλές αποδόσεις ορισμένων υποδεικτών του Γενικού Δείκτη Τιμών επηρεάζουν την πιθανότητα εμφάνισης ταυτόχρονων κοινών υπερβάσεων στις αποδόσεις (coexceedances) και άλλων υποδεικτών. / The aim of this thesis is to study the rapid dissemination Negative Financial Events (financial contagion) as presented in the literature as well as the causes, ways and methods of diffusion measurement. As far as the applied part of the existing literature is concerned, it is examined the part which concerns the examination of the Rapid Diffusion of Negative Financial Events (financial contagion) with limited dependent variable models. There is extensive analysis of the multinomial logit model. As part of this work it is presented an empirical application of such a model with data from the Greek stock market in order to indicate whether the low returns of certain subindices of the General Price Index affect the likelihood of simultaneous joint excesses in returns (coexceedances) of other subindices .