The member countries of the enlarged European Union show large differences in the structure of their tax systems. While consumption taxes have been largely harmonized over the past decades, differences remain in taxes on factor incomes, in particular on capital income. Also, effective tax rates on capital income in Central and Eastern European countries (CEEC) have been falling substantially over the last decade- a trend that may suggest that some tax competition has taken place in the enlarged European Union. The contribution of this paper is twofold. First, it presents and contrasts effective tax rates of Western European countries with those of the CEEC. Second, from a theoretical aspect, it presents a model framework within which a quantitative macroeconomic analysis of tax competition between the two regions can be conducted. In addition the model suggests that part of the large real exchange rate appreciation and current account deficits that CEE countries have experienced during the last decade might be attributed to effects from tax competition. (author's abstract) / Series: Discussion Papers SFB International Tax Coordination

The first chapter analizes conditional assistance programs. They generate conflicting relationships between international financial institutions (IFIs) and member countries. The experience of IFIs with conditionality in the 1990s led them to allow countries more latitude in the design of their reform programs. A reformist government does not need conditionality and it is useless if it does not want to reform. A government that faces opposition may use conditionality and the help of pro-reform lobbies as a lever to counteract anti-reform groups and succeed in implementing reforms. The second chapter analizes economies saddled with taxes and regulations. I consider an economy in which many taxes, subsidies, and other distortionary restrictions are in place simultaneously. If I start from an inefficient laissez-faire equilibrium because of some domestic distortion, a small trade tax or subsidy can yield a first-order welfare improvement, even if the instrument itself creates distortions of its own. This may result in "welfare paradoxes". The purpose of the chapter is to quantify the welfare effects of changes in tax rates in a small open economy. I conduct the simulation in the context of an intertemporal utility maximization framework. I apply numerical methods to the model developed by Karayalcin. I introduce changes in the tax rates and quantify both the impact on welfare, consumption and foreign assets, and the path to the new steady-state values. The third chapter studies the role of stock markets and adjustment costs in the international transmission of supply shocks. The analysis of the transmission of a positive supply shock that originates in one of the countries shows that on impact the shock leads to an inmediate stock market boom enjoying the technological advance, while the other country suffers from depress stock market prices as demand for its equity declines. A period of adjustment begins culminating in a steady state capital and output level that is identical to the one before the shock. The the capital stock of one country undergoes a non-monotonic adjustment. The model is tested with plausible values of the variables and the numeric results confirm the predictions of the theory.

Questo lavoro contribuisce al dibattito sul “decoupling delle Economie emergenti (EE) rispetto alle Economie Avanzate (EA)” rispondendo principalmente alle seguenti domande: “La vulnerabilità delle EE a schock esterni (siano essi reali o del credito) provenienti dalle EA è cambiata nel tempo? E’ cresciuta o si è ridotta, come implica l’ipotesi del decoupling?” Al fine di misurare l’impatto che un eventuale schock esterno avrebbe esercitato sulle EE in diversi periodi degli ultimi decenni, sono stati eseguiti esperimenti di analisi controfattuale utilizzando un modello econometrico Time Varying Panel VAR con coefficienti fattorizzati. Le analisi mostrano che negli ultimi trenta anni le EE sono diventate meno vulnerabili a shock provenienti dalle EA, siano essi di natura reale o shock del credito. Sebbene questo risultato supporti l’idea del decoupling, è importante notare che la resilienza delle EE a shock esterni è evoluta nel tempo in maniera non progressiva ma piuttosto evidenziando fasi di più forte resilienza seguite da fasi di minore resilienza e vice versa; un “sentiero a onde” non ancora pienamente considerato nella letteratura economica. Le EE sono inoltre risultate più vulnerabili a shock del credito rispetto a shock reali; questa maggiore vulnerabilità relativa ha raggiunto il suo picco negli anni più recenti. / This work aims to contribute towards the debate on “decoupling of Emerging Economies (EEs) from the Advanced Economies (AEs)” by addressing the following main questions: “Has the EEs’ vulnerability to external shocks (both real and credit shocks) coming from AEs changed over time? If so, has it grown or decreased, as the decoupling hypothesis claims?” In order to measure the impact that external shocks would have on the EEs’ GDP growth in different periods of last decades, counterfactual experiments were performed using an econometric Time Varying Panel VAR model with factorized coefficients. The analyses show that over the last thirty years EEs have become less vulnerable to shocks spreading from the AEs. Despite this represents evidence in favour of the decoupling hypothesis, it is important to note that EEs’ resilience to external shocks has changed in a non-progressive manner over time, with phases of greater resilience followed by others of lower resilience, and vice versa; this outlines a “wave-like” path whose evidence has yet been fully analyzed in the economic literature. Moreover, the EEs have shown to be more vulnerable to credit shocks than to real ones; this greater relative vulnerability has reached its peak in the most recent years.

Cette thèse traite des interactions entre les sphères financière et réelle de l'économie. Elle se compose de quatre chapitres. Dans les deux premiers chapitres, nous étudions l'existence et les fluctuations d'une bulle spéculative rationnelle, comme source de la volatilité des prix d'actifs, en prenant en compte les imperfections financières dans la modélisation des choix des ménages. L'existence d'un choix de portefeuille et de frictions financières favorisent l'émergence des fluctuations d'une bulle et des cycles économiques endogènes. Dans un tel contexte, nous analysons le rôle stabilisateur des politiques fiscales et/ou monétaires. Dans le chapitre 1, nous montrons qu'une politique monétaire répondant aux prix des actifs permet de stabiliser l'économie dans son ensemble. Dans le chapitre 2, nous comparons les vertus stabilisatrices d'un impôt progressif sur le revenu de capital à celles d'une politique monétaire régie par une règle de Taylor. Nous montrons qu'un impôt progressif sur le capital permet de stabiliser l'économie en réduisant la probabilité d'apparition des fluctuations endogènes, alors qu'une règle de Taylor a des vertus stabilisatrices mitigées. Nous étudions, dans le chapitre 3, l'existence de bulles rationnelles dans une économie ouverte à deux pays et la transmission internationale de leur éclatement. L'éclatement de la bulle dans un pays se transmet nécessairement à l'autre pays. L'effet de l'éclatement peut être positif ou négatif sur l'autre pays. Dans le chapitre 4, nous analysons le rôle de l'hétérogénéité sur la dynamique des prix d'actifs et les inégalités lorsque les agents ont des préférences pour la richesse. / This thesis deals with the interplay between the financial and real sectors of the economy. This thesis consists of four chapters. In the first two chapters, we study the existence and endogenous fluctuations of rational speculative bubbles, as a source of volatility in asset prices, taking into account the financial imperfections at the household level. We argue that the existence of a portfolio choice and financial frictions promote the emergence of bubble fluctuations and endogenous business cycles. In this context, we analyze the stabilizing role of fiscal and/or monetary policies. In Chapter 1, we show that a monetary policy responding to asset prices can stabilize the economy as a whole. In Chapter 2, we compare the stabilizing virtues of a progressive taxation on capital income with those of a monetary policy managed by a Taylor rule. We show that a progressive taxation on capital may rule out endogenous fluctuations, whereas a monetary policy under a Taylor rule has a mitigated stabilizing role. In Chapter 3, we study, the existence of rational bubbles in a two-country economy, and the international transmission of their bursting. A bubble bursting in a country necessarily transmits to the othercountry. The effect of a bubble crash in one country onthe bubble issued by the other country can be positive or negative. In Chapter 4, we analyze the role of heterogeneity on the dynamics of asset prices and inequalities when economic agents have preferences for wealth. Heterogeneity in preferences, but also in income, can heighten social inequalities and increase the asset price in the long run, but also promote asset price volatility in the short run.