This thesis analyses the interactions between politics, institutions, and policy outcomes using a political agency framework with incomplete information. After an introductory chapter, we develop a political agency model that is consistent with the empirical evidence on politically-induced fiscal cycles, and especially budget deficit cycles. We find that electoral concerns create, on average, a rising budget deficit prior to elections. The net welfare effect of elections is ambiguous: although they give rise to a deficit bias, they increase the quality of office-holders. The next chapter uses this microfounded model to study the incentive and welfare effects that the imposition of fiscal constraints has on policy makers' decision to create excessive deficits. Three types of constraints are investigated: deficit ceilings, a Golden Rule of public investment, and a balanced-budget rule. We find that constraints are effective in reducing excessive budget deficits - although at the expense of unconstrained instruments. Only one can yield higher welfare than the fully discretionary case. No appropriately designed fiscal constraint can achieve the first-best. In Chapter 4, we show that two key results in the political agency literature are not robust. The first is that a cutoff rule followed by voters in re-electing an incumbent always motivates the latter. The second is that this cutoff rule is an optimal incentive mechanism. Under symmetric incomplete information, the first result can be reversed since elections can reduce the experimentation effect of office-holders (i. e. the incentive to raise effort so that performance becomes a more accurate signal of ability). This reduction may more than offset the positive effect of elections on effort. When incentives to stand for office are modelled, result two can be overturned since a revealing equilibrium at the candidate entry stage can always be designed. This screens out low-ability citizens from policy making and therefore eliminates the adverse selection problem. If this latter is more important than moral hazard issues, the cutoff rule at the policy stage is no longer an optimal mechanism. In Chapter 5, we investigate in more details whether relevant (private) information about citizens' competence in political office (ability, honesty, etc. ) can be revealed by their entry and campaign expenditure decisions. We find that this depends on whether voters and candidates have common or conflicting interests; only in the former case can entry be revealing in equilibrium. We apply these results to Rogoff's (1990) Political Budget Cycles model, allowing for candidate entry: as interests are common, low-ability candidates are screened out at the entry stage, and so there is no signalling via fiscal policy. In a variant of the Rogoff model where citizens differ in honesty, rather than ability, interests are conflicting, and so the political budget cycle can persist in equilibrium. The final chapter concludes the thesis.

Chapter 2, titled "Hotelling Tax Competition" shows how competition among governments for mobile firms can bring about excessive differentiation in levels of taxation and public good provision. Hotelling's Principle of Minimum Differentiation is applied in the context of tax competition and shown to be invalid. Instead, when an equilibrium exists, differentiation of public good provision is maximized. Non-existence of equilibrium, which is possible, is a metaphor for intense tax competition. The chapter also shows that, to some extent, perfect tax discrimination presents a solution to the existence problem created by Hotelling tax competition, but that the efficiency problem of Hotelling tax competition is exacerbated. Chapter 3 shows how the institutional rules imposed on its signatories by the GATT created a strategic incentive for countries to liberalize gradually. Ree trade can never be achieved when punishment for deviation from a trade agreement is limited to a 'withdrawal of equivalent concessions' , the most severe form of punishment allowed (Article XXVIII). Retaliation is not allowed to entail higher tariffs than those set by the initial deviant. If, in addition, tariff bindings (Article 11) limit an initial deviation from an agreement in a similar way, then efficient self-enforcing tariff reductions must proceed in a series of steps or 'rounds'. Chapter 4 provides an answer to the question "Why are trade agreements regional? " It argues that free trade agreements (FTAs) are regional because, in their absence, optimal tariffs are higher against (close) regional partners than (distant) countries outside the region. Optimal tariffs shift rents from foreign firms to domestic citizens. Lower transport costs imply higher rents and therefore higher tariffs. So regional FTAs have a higher payoff than non-regional FTAs. Therefore, only regional FTAs may yield positive gains when sponsoring an FTA is costly. To analyze equilibrium, standard theory of non-cooperative networks is extended to allow for asymmetric players. Naive best response dynamics show that 'trade blocks can be stepping blocks' for free trade.

This thesis concerns itself with optimal learning through experimentation by microeconomic agents. The first part presents a model of a search process for the best outcome of many multi-stage projects. The branching structure of the search environment is such that the pay-offs to various actions are correlated; nevertheless, it is shown that the optimal strategy is given by a simple reservation price rule. A simple model of R&D is provided as an example. These general results are then applied in a model of job search and occupational choice in which jobs are grouped into occupations in a natural way. Before getting a job, the agent must first become qualified in the chosen occupation, at which point his general aptitude for jobs in this occupation is revealed. The search environment is such that the returns of jobs are correlated within a given occupation, but the optimal strategy is given by the above reservation value rule. One implication of this is that young inexperienced workers prefer to try riskier jobs/occupations first. Issues of job turnover and expected returns are addressed. The second part studies optimal experimentation by a monopolist who faces an unknown demand curve subject to random changes, and who maximises profits over an infinite horizon in continuous time. Two qualitatively very different regimes emerge, determined by the discount rate and the intensities of demand curve switching, and the dependence of the optimal policy on these parameters is discontinuous. One regime is characterised by extreme experimentation and good tracking of the prevailing demand curve, the other by moderate experimentation and poor tracking. Moreover, in the latter regime the agent eventually becomes ‘trapped’ into taking actions in a strict subset of the feasible set.

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Η Νουκλεολίνη είναι μια πρωτεΐνη που λειτουργεί ως υποδοχέας για διάφορα μόρια, όπως αυξητικοί παράγοντες, μόρια κυτταρικής προσκόλλησης, ακόμα και ιοί (HIV, coxsackie B, κ.ά.), που εμπλέκονται σε παθοφυσιολογικές διεργασίες. Συμμετέχει στις διαδικασίες της ογκογένεσης και της αγγειογένεσης και ανιχνεύεται στον πυρήνα, το κυτταρόπλασμα των κυττάρων, καθώς επίσης και στην επιφάνεια καρκινικών και μιτωτικά ενεργών ενδοθηλιακών κυττάρων. Το συνθετικό πεπτίδιο ΗΒ‐19 συνδέεται στη Νουκλεολίνη της επιφάνειας και καταστέλλει την ογκογένεση, αλλά και την αγγειογένεση Η ερευνητική ομάδα του εργαστηρίου έδειξε, σε προηγούμενες εργασίες, ότι το ΗΒ‐19 καταστέλλει την in vivo αγγειογένεση στο μοντέλο μελέτης της CAM σε έμβρυο όρνιθας. Βρέθηκε, ακόμη, ότι καταστέλλει την in vitro προσκόλληση, μετανάστευση και τον πολλαπλασιασμό των HUVEC, χωρίς να προκαλεί την απόπτωσή τους. Οι βιολογικές δράσεις αυτές φαίνεται να διαμεσολαβούνται και από τις κινάσες Src, ERK1/2, Akt και FAK, αφού παρατηρήθηκε ότι το ΗΒ‐19 καταστέλλει την ενεργοποίησή τους στα κύτταρα αυτά. Προκειμένου να διερευνηθεί ο μηχανισμός με τον οποίο το ΗΒ‐19 ασκεί τις βιολογικές του δράσεις, καθώς επίσης και η συμμετοχή της Νουκλεολίνης στη διαδικασία αυτή, HUVEC υπέστησαν παροδικό μετασχηματισμό με χρήση siRNA που στοχεύει το mRNA της Νουκλεολίνης. Η αποσιώπηση της Νουκλεολίνης εμπόδισε την κατασταλτική δράση του ΗΒ‐19 στον πολλαπλασιασμό και την προσκόλληση των HUVEC και, από το ίδιο πείραμα, φάνηκε ότι η Νουκλεολίνη είναι ένα κομβικό μόριο, καθώς η αποσιώπησή της ήταν από μόνη της ικανή να καταστείλει τις παραπάνω λειτουργίες. Για να επιβεβαιωθεί ότι η μεταγωγή σήματος του ΗΒ‐19 ενεργοποιείται από την αλληλεπίδρασή του με τη Νουκλεολίνη, μελετήθηκαν οι επιπτώσεις του στην ενεργοποίηση των κινασών Src και ERK1/2, σε παροδικά μετασχηματισμένα (με siRNA για Νουκλεολίνη) HUVEC.Παρατηρήθηκαν μειωμένα επίπεδα φωσφορυλίωσης των κινασών αυτών στα μετασχηματισμένα κύτταρα, συγκριτικά με τα φυσιολογικά. Ακόμη, η αποσιώπηση της Νουκλεολίνης εμπόδισε το ΗΒ‐19 να ασκήσει την κατασταλτική του δράση στη φωσφορυλίωσή τους. Συνοψίζοντας τα παραπάνω αποτελέσματα, φαίνεται ότι η αλληλεπίδραση του ΗΒ‐19 με τη Νουκλεολίνη πυροδοτεί οδούς μεταγωγής σήματος που μειώνουν τα επίπεδα φωσφορυλίωσης των Src και ERK1/2 και προκαλούν την καταστολή της προσκόλλησης και του πολλαπλασιασμού των HUVEC. Λαμβάνοντας υπ' όψιν και την υπάρχουσα βιβλιογραφία, φαίνεται πως το ΗΒ‐19 θα μπορούσε να χρησιμοποιηθεί στην αντικαρκινική θεραπεία ως μέρος μιας στρατηγικής με στόχο τη Νουκλεολίνη. / Nucleolin is a protein serving as a receptor for various ligands such as growth factors, cell adhesion molecules and viruses (e.g. HIV, coxsackie B), implicated in pathophysiological processes. It is overexpressed on the surface of tumour and mitotic endothelial cells and recent studies have demonstrated its involvement in tumour growth and angiogenesis. The synthetic peptide HB‐19 binds to the cell surface expressed Nucleolin and inhibits tumour growth and angiogenesis as well. The lab group has shown, in previous projects, that HB‐19 inhibits in vivo angiogenesis in the chicken embryo CAM assay. Evidence has been provided, in addition, that HB‐19 inhibits the in vitro adhesion, proliferation and migration of HUVEC, while not inducing their apoptosis. The aforementioned biological actions seem to be regulated by Src, ERK1/2, Akt and FAK kinases, as HB‐19 was found to inhibit their activation in HUVEC. In order to investigate the mechanism through which HB‐19 exerts the above described actions, as well as the involvement of cell‐surface Nucleolin in them, HUVEC were transiently transfected using siRNA targeting the mRNA of Nucleolin. The inhibitory effect of HB‐19 in cell proliferation and adhesion was blocked by the knockdown of Nucleolin and, as was shown by the same experiment, Nucleolin is a crucial factor to HUVEC proliferation and adhesion, since both processes were inhibited by the down‐regulation of Nucleolin expression. In order to confirm that HB‐19 signaling is activated by its reaction with Nucleolin, its effect on the activation of Src and ERK1/2 was tested on transiently transfected HUVEC (using siRNA for Nucleolin). A decrease in phosphorylation levels of Src and ERK1/2 was induced on the transfected cells, compared to wild type cells. Furthermore, Nucleolin knockdown blocked HB‐19‐induced Src and ERK1/2 inactivation. In conclusion, these results indicate that HB‐19's interaction with Nucleolin triggers a signal transduction pathway that reduces the phosphorylation levels of Src and ERK1/2 and causes inhibition of HUVEC proliferation and adhesion. Thereof, HB‐19 could constitute a potentially interesting tool for tumour therapy, as part of a Nucleolin targeting strategy.

The primary objective of the thesis is to investigate whether African banks use loans loss provisions estimates to smooth reported earnings, and to determine the factors that influence the extent of earnings smoothing among African banks. Earnings smoothing via loan loss provision has been examined in several regions, but the case of Africa remain unexplored in the literature. In the thesis, earnings smoothing is viewed as an earnings management practice while loan loss provisions estimate is considered to be the tool used by African banks to smooth reported earnings. Using African bank data obtained from Bankscope database, I test the earnings smoothing hypothesis for 370 African banks during the 2002 to 2014 period using the specific-accrual approach. The specific-accrual approach estimates a specific discretionary accrual as a function of its non-discretionary determinants and other factors that influence the manipulation of the specific accrual. The model specification expresses discretionary loan loss provisions as a function of earnings before provisions and tax, its non-discretionary determinants and other factors that influence the decision regarding the level of bank provisions for each period. The findings indicate that African banks manipulate loan loss provisions estimates to smooth reported earnings and this behaviour is influenced by bank differences, accounting disclosure differences and institutional differences across African countries. The primary contribution to knowledge of the thesis is its extension of our understanding of the role of discretionary accruals in the bank financial reporting, focusing on African banks - a context that has not been extensively examined in the literature. Also, the thesis extends the bank earnings smoothing debate to the African context and the findings of this study are useful to bank regulators in Africa in their evaluation of whether bank loan loss provisions solely reflect credit risk considerations or whether bank loan loss provisions estimates reflect opportunistic considerations of African bank managers. Finally, the findings are useful to local accounting standard setters in the region in their evaluation of several accounting numbers that bank managers might use to manipulate reported earnings.

Parking plays an important role in mobility, access and the economic development of cities; at the same time, it is a profitable business for both the private and public sectors. The city centre car parking market is a sector of the economy that has increased in importance as the market for cars has grown. Cars have become a fundamental element of journey mobility and, in consequence, parking has as well. The car-parking sector has always been of great importance in terms of urban mobility, since it is a fundamental element in achieving a high level of accessibility in the city centres. In fact, many businesses and municipalities see an adequate supply of parking, especially for visitors, as crucial for their competitive growth. Yet, at the same time parking is, and will remain for most cities, the most powerful means of traffic restraint available. The economics of car parking is also important because it is, both for public and private organizations, a key source of revenue. Despite the importance of the sector, knowledge of the car parking market has been until very recently, sparse and limited. This thesis is focused on the car parking operator?s point of view, analysing and appraising this industry and the actors involved. The related literature investigates the car parking sector analysing the variables that influence its behaviour. The literature review also appraises whether and how far car parking operators are considered as key transport actors by local and national authorities, comparing Italy and the UK. The information collected is used to structure an econometric model, using the variables chosen as important and simulating the strategic behaviour of the car parking operator in a city centre context. The research also deepens the analysis of the car parking sector with a survey of car parking operators and policies in some Italian and UK cities. In this way the research achieves its aims to contribute to filling the knowledge gap on the city centre car parking market, both theoretically and empirically. Theoretically because the literature on car parking is very recent and little investigated; empirically, because research in this field is also sparse.

Chapter 1: We propose an integral correction mechanism to model real exchange rate dynamics. In estimation, we also allow a Harrod-Balassa-Samuelson effect on real exchange rate long-run equilibrium. Using data from 19 OECD countries, we find the integral correction mechanism fitting in-sample data significantly better than the popular smooth transition autoregression model. The special dynamics of the integral correction mechanism help explain the PPP puzzle by distinguishing mean-reversion speeds in the long- and short- run. However, the integral correction mechanism shows a significant out-of-sample forecast gain over the random walk in only few cases. Though the gain is robust across forecast horizons and quite large at long horizons. Chapter 2: This chapter evaluates the ability of a standard IRBC model augmented with an input adjustment cost of imported goods to explain different aspects of the real exchange rate like the standard deviation, the autocorrelation function, the spectrum and the integral correction mechanism. I find that the simple IRBC model with an appropriate calibration can well capture all features of the real exchange rate. The input adjustment cost plays the key role. As compared to the standard model, it implies a reversed impulse response of the real exchange rate with a fast speed going back to steady state and introduces a long-run cyclical movement in most macroeconomic variables. I find that this particular impulse response helps explain the PPP puzzle. Chapter 3: I study optimal unconventional monetary policy under commitment in a two-country model where domestic policy entails larger spillovers to foreign countries. Equity injections into financial intermediaries turn out to be more efficient than discount window lending and the large-scale asset purchases that have been employed in many countries. Due to precautionary effects of future crises, a central bank should exit from its policy more slowly than the speed of deleveraging in the financial sector. The optimal policy can be changed considerably if cross-country policy cooperation is not imposed. In this case, interventions tend to be too strong in one country but too weak in the other. Gains from cooperation become positive if using unconventional monetary policy is costly enough, then correlates positively with the cost. Chapter 4: I consider the implementation of optimal unconventional monetary policy outlined in chapter 3. I find the Ramsey policy characterised by a simple rules responding to gaps in asset prices. However, it requires knowledge of asset prices that would be realized in a world free of financial friction so cannot be used to guide unconventional monetary policy in practice. The best practical simple rule responds to credit spread with inertia.

This dissertation consists of the three essays; in these three essays I study different areas of trade integration among Gulf Cooperation Council Countries (GCC) by examining the effect of GCC Free Trade Agreement (GCC FTA) on trade among GCC countries during the 1983-2010 period. In the three essays, different variations of the gravity model of international trade are applied to a set of bilateral trade flows among 54 countries representing GCC countries and their major trade partners during the 1978-2010 period. The first essay is presented in chapter two, where I investigate the effect of GCC FTA on aggregate trade among GCC countries. The findings of chapter two suggest that GCC FTA has resulted in trade creation among GCC countries during the 1983-2010 period. The second essay is presented in chapter three, where I investigate the effect of GCC FTA on intra-industry trade among GCC countries. Investigating GCC FTA effects for disaggregate trade is important, as the aggregate results may suffer from aggregation bias. Also, it helps identify the sectors that benefit more from GCC FTA which is an important issue for GCC countries that are seeking diversification of their economies. Chapter three results suggest that GCC FTA trade creation was more concentrated in sectors that exhibit lower shares of GCC intra-trade during the 1983-2010 time period. The third essay is presented in chapter four where I investigate whether GCC FTA trade creation/destruction effect (aggregate and intra-industry trade) among GCC countries was attributed mainly to new trade relations (extensive margin) or to existing trade relations (intensive margin), and whether GCC FTA led to an increase in new trade relations among GCC countries. Chapter four results suggest that GCC FTA trade creation is attributed mostly to trade along the intensive margin while GCC FTA has a negative effect on trade along the extensive margin for most trade sectors. Overall, the results of the three essays suggest that trade integration among GCC countries is not very deep. Although GCC FTA is effective at the aggregate level, however GCC FTA failed to promote trade among GCC countries in larger intra-trade industries and failed in creating trade in new products among GCC countries. GCC countries have plans for a unified currency, since a unified currency requires deeper levels of economic integration than those needed for an FTA, the shallow level of trade integration maybe a sign that GCC economies are not yet ready to adopt a unified currency.

Since the late1990s, theorists have attempted to understand an apparent securitization of development within the policies produced by global governance networks and institutions (Beall et al., 2005; Duffield, 2007; Woods, 2005). The key assumptions central to much of the securitization of development debate are that; significant areas of the South are excluded from formal global economic networks, but are reintegrating through parallel economic activity; the discourses of security and development are linked by global governance institutions, such that significant areas of the South are conceived as an international security threat; the major agencies of global governance are unified through a liberal consensus, and pursue liberal change through the distribution of aid and through development programmes. This research is concerned with the ways in which this debate aids our understanding of contemporary global governance, and its limitations. This theoretical and empirical evaluation takes a number of forms including: an analysis of the policy discourse of key global governance institutions; an examination of world economic trends; a statistical project investigating the distribution of development aid; and a case study of development programming. This thesis argues that the securitization of development debate aids our understanding of global governance through its identification of both liberal societal transformation as a key rationale of global governance and the security development nexus as a central framework for North-South relations. It further provides important insights into the productive power of liberal global governance networks and develops a fruitful application of post-structural analysis to the problematic of global development. This research also identifies theoretical and empirical limitations within this debate. In light of these, an approach is proposed which takes greater account of firstly, the structural dynamics of the global economy and secondly, the internal contradictions and complexities inherent within the discourses of global governance. The former would involve greater engagement with the literature that demonstrates a complex and varied picture of global economic expansion and contraction. This research further suggests that the effect of the axiom that there can be no development without security is ambiguous. And also argues that the suggestion that global governance pursues liberal change through the distribution of aid needs qualification. Finally, further analysis to determine the utility of engaging with the governmentality literature is proposed.