This thesis investigates different issues related to the issuance of debt by sovereign bodies such as governments, under uncertainty about the future interest rates. Several dynamic models of interest rates are presented, along with extensive numerical experiments for calibration of models and comparison of performance on real financial market data. The main contribution of the thesis is the construction and demonstration of a stochastic optimisation model for debt issuance under interest rate uncertainty. When the uncertainty is modelled using a model from a certain class of single factor interest rate models, one can construct a scenario tree such that the number of scenarios grows linearly with time steps. An optimization model is constructed using such a one factor scenario tree. For a real government debt issuance remit, a multi-stage stochastic optimization is performed to choose the type and the amount of debt to be issued and the results are compared with the real issuance. The currently used simulation models by the government, which are in public domain, are also reviewed. Apparently, using an optimization model, such as the one proposed in this work, can lead to substantial savings in the servicing costs of the issued debt

Public debt managers have a certain range of borrowing instruments varying in their interest rate type, currency, maturity etc. at their disposal and have to find an appropriate combination of those while raising debt on behalf of the government. In selecting the combination of instruments to be issued, i.e. the borrowing strategy to be pursued for a certain period of time, debt managers need to consider several objectives that are conflicting by their nature, and the uncertainty associated with the outcomes of the decisions made. The objective of this thesis is to propose an approach to support the decision making process regarding sovereign debt issuance. We incorporate Multi-Criteria Decision Making (MCDM) tools using a multi-period stochastic programming model that takes into account sequential decisions concerned with debt issuance policies. The model is then applied for public debt management in Turkey.

Management of public debt is crucial for every country. Public debt managers make efforts to both minimize the cost of borrowing and to keep debt stock at sustainable levels. However, due to competition for funds in the continuously changing and developing financial markets, new threats and opportunities appear constantly. Public debt managers construct borrowing policies in order to minimize the cost of borrowing and also to decrease risk by using various borrowing instruments. This thesis presents a mathematical model to determine the borrowing policy that minimizes the cost of borrowing in line with future projections and then seeks to extend it to construct risk sensitive policies that allow minimizing the effects of changes in the market on the cost of borrowing. The model&rsquo / s application results for determining the borrowing strategies of Turkish Treasury for 100 month horizon have been evaluated through the study.

Fluctuation of exchange rate has affected the increasing burden of foreign debt payment in emerging economies. This issue has negatively influenced the economic growth. It has been a severe obstacle considering that governments have to issue public debt denominated in foreign currency to finance the budget deficit. Hence, there is an urgent necessity to implement an efficient public debt management to minimize the exchange rate exposure. This thesis analyses how efficient the foreign debt portfolio management is in the 14 emerging economies under examination in the period of 1990-2013. Panel Dynamic Fixed-effect Estimator and Granger Causality approach are applied to analyze how responsive the currency composition of foreign debt portfolio to the exchange rates movement. The thesis examines the four biggest foreign debt shares that are denominated in US dollar, Euro, British pound, and Japanese yen, and the related exchange rates movement in the economies under consideration. The observation concludes that the foreign debt portfolio management in these emerging economies is not efficient or not optimal. The evidences prove that changes in the exchange rates of Euro, British pound, and Japanese yen relative to US dollar Granger cause changes in respected debt shares. It means that there is no substitution effects from the appreciation of the currencies vis-à-vis the US dollar during the year of observation.

L’objectif de cette thèse est d’étudier la soutenabilité de la dette publique en fonction du niveau de développement des pays. Après avoir revu la littérature économique en matière d’indicateurs de soutenabilité de la dette, nous avons appliqué des méthodes empiriques et statistiques pour analyser la viabilité de la dette des pays développés et en développement. Nous avons ainsi estimé une fonction de réaction budgétaire pour les gouvernements des pays du G7 qui révèle que les gouvernements des pays du G7 ne se sont pas souciés de l’équilibre de leurs finances publiques sur la période 1978-2007 ; et qu’il y a une attention particulière à la soutenabilité des finances publiques au sein de pays appartenant l’union monétaire européenne. Ensuite, nous avons analysé la soutenabilité de la dette de la Côte d’Ivoire, par le biais de méthodes statistiques utilisées par les Institutions Financières Internationales. Le pays présente ainsi un risque modéré du profil d’endettement ; et l’assainissement de ses finances publiques est essentiel pour la viabilité de la dette à long terme. Par ailleurs, l’évaluation de la performance de la gestion de la dette publique ivoirienne révèle que la conception d’une réelle politique nationale d’endettement permettrait de combler les insuffisances des dispositifs existants. En définitive, les conclusions de notre étude suggèrent des réflexions supplémentaires sur l’analyse théorique de la soutenabilité et sur la cadre de gestion internationale de la dette publique. / The purpose of this thesis is to analyse public debt sustainability according to the level of national economic development. After reviewing the economic literature on public debt sustainability indicators, we applied specific empirical methods to compare developed countries and analyse a heavily indebted poor country (HIPC). We first estimated, among G7 governements, an error-correction-type policy reaction function based on an iterative bayesian estimation that compares the different dynamics of public debt evolution. This analysis reveals that on one hand G7 governments did not focus on debt sustainability during the time frame (1978-2007) ; on the other hand, we noticed a particular attention to debt sustainability in Eurozone countries (Germany, France, Italy) as compared to other countries in the sample. Next, we analyzed the debt sustainability of Côte d’Ivoire, a sub-Saharan Heavily Indebted Poor Country using statistical methods developed by the IMF and the World Bank. The results showed that the country has a moderate risk to indebtment ; therefore budget stabilization and diversification of its exports will be critical for its long-term debt sustainability. Beyond these objectives, the evaluation of the public debt management process, based on an international method (DeMPA), also highlights that designing a real national debt policy could fulfill the shortcomings of current policies. Overall, the conclusions of our thesis suggest additional researches and reflections on the theoretical analysis of public debt and on the architecture of the international public debt management frameworks.

Tyrimo objektas – valstybės skola. Tyrimo tikslas – įvertinus Lietuvos valstybės skolą, ištirti jos poveikį socialinėms išlaidoms. Uždaviniai: 1. Pateikti valstybės skolos sampratą bei valstybės skolinimosi poreikį sąlygojančius veiksnius. 2. Apibrėžti valstybės skolos naštą ir skolinimosi reikšmę ekonomikai. 3. Pateikti valstybės skolos vertinimo kriterijus. 4. Įvertinti Lietuvos valstybės skolą tarp ES valstybių pagal išskirtus vertinimo kriterijus. 5. Nustatyti Lietuvos valstybės skolos poveikį socialinėms išlaidoms bei palyginti jį su kitomis ES šalimis. Tyrimo metodika. Valstybės skolos sampratai bei valstybės skolinimosi poreikio nustatymui naudoti bendramoksliniai tyrimo metodai – mokslinės literatūros bei teisinių dokumentų analizė ir sintezė. Atliekant Lietuvos valstybės skolos analizę – statistinių duomenų rinkimo bei analizės metodai, palyginimo, grafinio vaizdavimo būdai, loginė analizė ir sintezė. Pritaikius regresinę analizę nustatytas Lietuvos valstybės skolos poveikis socialinėms išlaidoms. Lyginamosios analizės dėka šis poveikis įvertintas Europos Sąjungos šalių kontekste. Tyrimo rezultatai. Pirmojoje darbo dalyje pateikta valstybės skolos samprata, valstybės skolinimosi poreikį sąlygojantys veiksniai, skolinimosi reikšmė ekonomikai, išanalizuoti ir susisteminti skolos naštos modeliai. Antrojoje darbo dalyje, išanalizavus įvairių mokslininkų darbus, pateikti valstybės skolos vertinimo kriterijai, nustatyta valstybės skolos sudėties svarba, pateiktas... [toliau žr. visą tekstą] / Object of the research – public debt. Aim of the research – to evaluate the Lithuanian public debt, to assess its influence on social expenditure. Objectives of the research: 1. to present the concept of public debt and to discuss the factors, which influence government borrowing needs; 2. to define the debt burden and to determine the effect of public debt on economy; 3. to provide the public debt evaluation criteria; 4. to evaluate the Lithuanian public debt in respect to the situation in the EU countries according to the identified criteria; 5. to determine the impact of the Lithuanian public debt on social expenditure and to compare it with that in other EU countries. Research methods. Analysis and synthesis of scientific literature and legal documents, statistical data collection and analysis methods, comparative analysis, graphical representation techniques, logical analysis, regression analysis. Research results. Part One introduces the concept of public debt, analyzes the factors influencing government borrowing needs, importance of borrowing to economy and structured models of debt burden. Part Two, having analyzed various scientific articles, provides criteria of the public debt evaluation, reasons importance of the public debt composition and presents the assessment model of the impact of public debt on social expenditure. Part Three gives structural and dynamic analysis of the Lithuanian public debt, evaluates the amount of public debt, according to the... [to full text]

This thesis describes the actual trends of accumulation of the public indebtedness and the various views on the existence of fiscal deficit and public debt. The main purpose of the thesis is to analyze the public debt management - its objectives, operations and organisation. The quantitative criteria for debt portfolio determined by the Ministry of Finance of the Czech Republic are analyzed and compared with the development and structure of the czech central government debt. The analytical part of the thesis includes the rules for issuance of the government bonds, the analysis of the interest costs and the thoughts about the sustainability of the czech central government debt.

Valstybės skola ir jos atsiradimo priežastys svarbios ekonomikos mokslo dalykui, nes tai valstybės ekonomikos vystimuisi reikšmingas veiksnys. Didelė valstybės skola yra našta šalies ekonomikai, kadangi kuo didesnė skola, tuo daugiau valstybės biudžeto lėšų reikia skirti jos aptarnavimui, t.y. palūkanų mokėjimams ir pačios skolos grąžinimui. Tačiau nesiskolinti valstybė taip pat negali. Biudžeto deficitas, stambūs investiciniai projektai, kurių įgyvendinimui reikalingos didelės lėšos ir kitos priežastys lemia skolos atsiradimą ir tolesnį jos vystimąsi. Šiuolaikiniam šalies gyventojui yra aktuali valstybės biudžeto tvarkymo sistema, kadangi nuo to, koks valstybės biudžetas ir valstybės skola, priklauso gyventojų socialinė aplinka, net gyvenimo lygis, tad svarbu išsiaiškinti, koks optimalus turi būti skolos dydis, kad teigiamai veiktų ekonomiką, ir būtinai rasti būdų, kaip tinkamai ir racionaliai vykdyti valstybės skolos valdymą. / Public debt and the causes of economic research relevant to the subject matter, as the state of economic development is a significant factor. High level of debt is a burden to the economy because the larger the debt, the more the state budget funds should be used with its service, ie interest payments and repayment of the debt. Nesiskolinti But the state also can not. The budget deficit, large investment projects, whose implementation would require significant resources and other reasons for the emergence of the debt and further development. Tje budget management system is topical for the modern capita of the state, since that what the state budget and public debt, the population belongs to the social environment, even the standard of living, it is important to clarify what must be the optimal amount of debt, make a positive contribution to the economy, and it must find ways to the proper and rational exercise of public debt management.

It can be difficult for a sovereign debt manager to see the implications on expected costs and risk of a specific debt management strategy, a simulation model can therefore be a valuable tool. This study investigates how future economic data such as yield curves, foreign exchange rates and CPI can be simulated and how a portfolio optimization model can be used for a sovereign debt office that mainly uses financial derivatives to alter its strategy. The programming language R is used to develop a bespoke software for the Swedish National Debt Office, however, the method that is used can be useful for any debt manager. The model performs well when calculating risk implications of different strategies but debt managers that use this software to find optimal strategies must understand the model's limitations in calculating expected costs. The part of the code that simulates economic data is developed as a separate module and can thus be used for other studies, key parts of the code are available in the appendix of this paper. Foreign currency exposure is the factor that had the largest effect on both expected cost and risk, moreover, the model does not find any cost advantage of issuing inflation-protected debt. The opinions expressed in this thesis are the sole responsibility of the author and should not be interpreted as reflecting the views of the Swedish National Debt Office. / Det kan vara svårt för en statsskuldsförvaltare att se påverkan på förväntade kostnader och risk när en skuldförvaltningsstrategi väljs, en simuleringsmodell kan därför vara ett värdefullt verktyg. Den här studien undersöker hur framtida ekonomiska data som räntekurvor, växelkurser ock KPI kan simuleras och hur en portföljoptimeringsmodell kan användas av ett skuldkontor som främst använder finansiella derivat för att ändra sin strategi. Programmeringsspråket R används för att utveckla en specifik mjukvara åt Riksgälden, men metoden som används kan vara användbar för andra skuldförvaltare. Modellen fungerar väl när den beräknar risk i olika portföljer men skuldförvaltare som använder modellen för att hitta optimala strategier måste förstå modellens begränsningar i att beräkna förväntade kostnader. Delen av koden som simulerar ekonomiska data utvecklas som en separat modul och kan därför användas för andra studier, de viktigaste delarna av koden finns som en bilaga till den här rapporten. Valutaexponering är den faktor som hade störst påverkan på både förväntade kostnader och risk och modellen hittar ingen kostnadsfördel med att ge ut inflationsskyddade lån. Åsikterna som uttrycks i den här uppsatsen är författarens egna ansvar och ska inte tolkas som att de reflekterar Riksgäldens syn.