[pt] Esta tese é composta por 3 capítulos. No primeiro capítulo mostro que quando um banco central não é totalmente apoiado financeiramente pelo tesouro e enfrenta uma restrição de solvência, um aumento no tamanho ou uma mudança na composição de seu balanço pode servir como um mecanismo de compromisso em um cenário de armadilha de liquidez. Em particular, quando a taxa de juros de curto prazo está em zero, operações de mercado aberto do banco central que envolvam compras de títulos de longo prazo podem ajudar a mitigar a deflação e recessão sob um equilíbrio de política discricionária. Usando um modelo simples com produto exógeno, mostramos que uma mudança no balanço do banco central, que aumenta seu tamanho e duração, incentiva o banco central a manter as taxas de juros baixas no futuro, a fim de evitar perdas e satisfazer a restrição de solvência, aproximando-se de sua política ótima de commitment. No segundo capítulo da tese, eu testo a validade do novo mecanismo desenvolvido no capítulo 1, incorporando um banco central financeiramente independente em um modelo DSGE de média escala baseado em Smets e Wouters (2007), e calibrando-o para replicar principais características da expansão do tamanho e composição do balanço do Federal Reserve no período pós-2008. Eu observo que os programas QE 2 e 3 geraram efeitos positivos na dinâmica da inflação, mas impacto modesto no hiato do produto. O terceiro capítulo da tese avalia as consequências em termos de bem-estar de regras fiscais simples em um modelo de um pequeno país exportador de commodities com uma parcela da população sem acesso ao mercado financeiro, onde a política fiscal assume a forma de transferências. Uma constatação principal é que as regras orçamentárias equilibradas para as receitas de commodities geralmente superam as regras fiscais mais sofisticadas, em que as receitas de commodities são salvas em um Fundo de Riqueza Soberana. Como os choques nos preços das commodities são tipicamente altamente persistentes, a renda atual das famílias está próxima de sua renda permanente, tornando as regras orçamentárias equilibradas próximas do ideal. / [en] This thesis is composed of 3 chapters. In the first chapter, It s shown that when a central bank is not fully financially backed by the treasury and faces a solvency constraint, an increase in the size or a change in the composition of its balance sheet (quantitative easing - QE) can serve as a commitment device in a liquidity trap scenario. In particular, when the short-term interest rate is at the zero lower bound, open market operations by the central bank that involve purchases of long-term bonds can help mitigate deflation and recession under a discretionary policy equilibrium. Using a simple endowment-economy model, it s shown that a change in the central bank balance sheet, which increases its size and duration, provides an incentive to the central bank to keep interest rates low in the future to avoid losses and satisfy its solvency constraints, approximating its full commitment policy. In the second chapter, the validity of the novel mechanism developed in chapter 1 is tested by incorporating a financiallyindependent central bank into a medium-scale DSGE model based on Smets and Wouters (2007), and calibrating it to replicate key features of the expansion of size and composition of the Federal Reserve s balance sheet in the post-2008 period. I find that the programs QE 2 and 3 generated positive effects on the dynamics of inflation, but mild effects on the output gap. The third chapter of the thesis evaluates the welfare consequences of simple fiscal rules in a model of a small commodity-exporting country with a share of financially constrained households, where fiscal policy takes the form of transfers. The main finding is that balanced budget rules for commodity revenues often outperform more sophisticated fiscal rules where commodity revenues are saved in a Sovereign Wealth Fund. Because commodity price shocks are typically highly persistent, the households current income is close to their permanent income, so commodity price shocks don t need smoothing, making simple balanced budget rules close to optimal.

The Diploma thesis deals with unconventional monetary policies,that important central banks used in order to cope with global financial and economic crisis in recent years. Goals of the paper is to introduce the most significant unconventional monetary policies, analyze their effectivity in selected countries (Japan, USA, Great Britain, eurozone and Czech republic), and statistically test impact of these nonstandard approaches on international trade.

Cette thèse traite de deux nouveaux débats sur le central banking qui ont émergé après la crise financière de 2008: le débat sur les pertes financières aux bilans des banques centrales, et le débat sur le niveau élevé des taux bancaires par rapport aux taux de marché après la crise. Les deux premiers chapitres s’inscrivent dans le premier débat. Le lien entre la solidité financière des banques centrales et l’inflation est étudié empiriquement dans le premier chapitre, en se basant sur un large panel de 82 pays. Théoriquement, ce lien est potentiellement présent lorsque le gouvernement ne soutient pas financièrement la banque centrale et que celle-ci ne peut donc compter que sur elle-même pour améliorer sa situation financière. Les résultats du premier chapitre montrent qu’en pratique tel est effectivement le cas: les détériorations aux bilans des banques centrales s’accompagnent d’une inflation plus forte lorsque la banque centrale n’a pas de soutien fiscal. Les résultats ne montrent pas de lien dans un contexte général, comme la théorie le suggère. Dans le second chapitre, il est analysé et conceptualisé l’argument selon lequel une banque centrale peut mettre fin à un régime de change fixe ou quasi-fixe par peur de futures pertes financières. L’analyse est ensuite appliquée au cas du cours plancher mis en place par la Banque Centrale de Suisse (BNS) entre 2011 et 2015 vis-à-vis de l’euro. Cet argument a été avancé par beaucoup pour expliquer la fin de la politique de cours plancher en Suisse, sans qu’aucune recherche avant celle-ci n’évalue sa pertinence. Les estimations empiriques du Chapitre 2 permettent de montrer que cet argument avait une crédibilité: elles montrent que dans des scénarios crédibles, en cassant le peg avec l’euro 17 mois plus tard, la BNS aurait essuyé une perte considérable, dépassant un seuil perçu comme limite par beaucoup de banquiers centraux. Le dernier chapitre de cette thèse s’intéresse à l’écart entre les taux de dépôts et le taux de marché en zone euro (l’EURIBOR) qui est devenu significativement positif après la crise, conduisant certains à parler de « sur-rémunération » des dépôts. Ce chapitre soutient que la majorité de cet écart ne s’explique non pas par un comportement anormal des dépôts comme certains l’ont avancé, mais au contraire par une perte de pertinence de l’EURIBOR. Construisant une alternative à l’EURIBOR, ce chapitre conclut que le risque bancaire a eu une influence primordiale sur le niveau de rémunération des dépôts dans le monde d’après-crise. / This thesis deals with the new debates on central banking which arose after the 2008 global financial crisis. More particularly, two of such debates are addressed: the debates on the financial losses in central banks’ balance sheets, and the debates on the high level of bank rates compared to market interest rates following the financial crisis. The two first chapters are related to the first debate. The link between central bank financial strength and inflation is empirically examined in a large sample of 82 countries. Theoretically, this link is potentially present when the government does not fiscally support the central bank, so that the central bank can only rely on itself to improve its financial situation. The results show that in practice central bank balance sheet deteriorations indeed lead to higher inflation when fiscal support is absent. The results, based on a particularly meticulous and consistent sample selection, do not show the presence of a link between the two variables in a general context, as the theory suggests. In the second chapter, I analyze and conceptualize the argument according to which a central bank can end a peg exchange rate regime by fear of making significant losses in the future, and I apply this analysis to the Swiss franc peg between 2011 and 2015. This argument was brought forward by many commentators to explain the Swiss move, while no research before this one did study the relevance of this argument. The empirical estimates in Chapter 2 show that this argument indeed had some credibility: under some credible scenarios the Swiss central bank would have incurred significant losses by breaking its peg 17 months later, with losses exceeding a threshold judged as relevant by many central bankers. The last chapter of this thesis focuses on the spread between deposit rates and market interest rates in the Eurozone (more specifically, the EURIBOR), which became significantly positive after the financial crisis, leading some commentators to claim that deposits were over-remunerated. This chapter upholds that the major part of this spread is not due to an « abnormal » behavior of deposits but is rather due to the fact that the EURIBOR has become irrelevant after the global financial crisis. Building an alternative to the EURIBOR, the chapter concludes that banking risks have been having a major influence on the level of deposit remuneration.