This dissertation consists of three essays on income risk and aggregate demand over the business cycle, each addressing an aspect of the Great Recession. The first chapter reframes the standard liquidity trap model to illustrate the costly feedback loop between idiosyncratic risk and aggregate demand. I first show that a liquidity trap can result from excess demand for precautionary savings in times of high uncertainty. Second, I show that the output and welfare costs of the ensuing recession depend crucially on how the drop in demand for output is translated into a reduction in demand for labor. Increased unemployment risk compounds the original rise in idiosyncratic productivity risk and reinforces precautionary motives, deepening the recession. Third, I show that increasing social insurance can raise output and welfare at the zero bound. I decompose these effects to distinguish the component unique to the liquidity trap environment and show that social insurance is most effective at the zero bound when it targets the type of idiosyncratic risk households face, which in turns depends on the labor market adjustment mechanism. The second paper offers a novel model of the connection between the consumer credit and home mortgage markets through an individual’s credit history. This paper introduces a novel justification for the home mortgage interest deduction. In an economy with both housing assets and consumer credit, the mortgage interest deduction is modeled as a subsidy for the accumulation of collateralizable assets by households who have maintained good credit. As such, the subsidy loosens participation constraints and facilitates risk-sharing. Empirical evidence and a calibration exercise reveal that the subsidy has a sizable impact on the availability of credit. The third paper assesses the role of policy uncertainty in the Great Recession. The Great Recession features substantial geographic variation in employment losses, a fact that is often presented as a challenge to uncertainty-based models of the downturn. In this paper we show that there is a substantial correlation between the distribution of employment losses and the increases in local measures of both economic and policy uncertainty. This relationship is robust across a wide range of measures. / Economics

This paper deals with the integration of Walras' law into Keynesian macroeconomics and the attempts at a consistent specification of period models (beginning- vs. end-of-period-equilibrium). Three examples are examined where neglect of a consistent specification led to erroneous results: (1) the identification of the IS-condition with equilibrium of the "flow market" for bonds, (2) superficial treatments of the liquidity trap, and (3) the assumptions on the stochastic structure of monetary and real shocks in determining the optimal monetary instrument. (author's abstract) / Series: Department of Economics Working Paper Series

This diploma thesis focuses on changes in the external balance of Portugal, Italy, Greece and Spain in the period of financial and economic crisis after 2008. The theoretical framework is based on an exact definition of external balance, ultimately as neither surplus nor deficit of a relevant balance in terms of balance of payments. Potential impacts of monetary and fiscal policies on the external balance are described there as well, using the IS-LM-BP model. The second part of the thesis, which employs this theory, is mainly based on an analysis of relevant balances of payments of the aforementioned countries, focusing on their external balance in the period before as well as during the economic crisis. The aim of the analysis is to identify the main causes of external imbalance in the Southern European countries and to find out whether these played a key role as a trigger and accelerator in their recession after 2008. Specific changes during the crisis identified in balances of payments will also be depicted in the IS-LM-BP model. Leading to the conclusion, the outcomes of a correlation analysis are used as well, looking into causal relationships between specific balance of payments variables on the one hand, and macroeconomic variables on the other. A minor part also deals with the role played in this context by the TARGET2 payment system and answers the question to which extent this system took part in the elimination of the external imbalance of the Southern European countries during the crisis.

The central bank is not able to further ease monetary conditions once it ex- hausts the space for managing short-term policy rate. Then it has to turn its attention to unconventional measures. The thesis provides a discussion about the suitability of different unconventional policy tools in the Czech situation while the foreign exchange (FX) interventions have proven to be the most appropriate choice. A New Keynesian small open economy DSGE model estimated for the Czech Republic is enhanced to model the FX interventions and to compare dif- ferent monetary policy rules at the zero lower bound (ZLB). The thesis provides three main findings. First, the volatility of the real and nominal macroeconomic variables is magnified in the response to the domestic demand shock, the for- eign financial shock and the foreign inflation shock. Second, the volatility of prices decreases significantly if the central bank adopts price-level or exchange rate targeting rule. Third, intervening to fix the nominal exchange rate on some particular target or to correct a misalignment of the real exchange rate from its fundamentals serves as a good stabilizer of prices while intervening to smooth the nominal exchange rate movements increases the overall macroeconomic volatility at the ZLB. 1

[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.

This diploma thesis describes the Quantitative easing as an unconvetional tool of the monetary policy. In the first chapter of this thesis there is theoretical analysis of the zero lower bound and also of specific phenomenon that might occur in this situation (the liquidity trap). The second chapter deals with the quantitative easing as a monetary policy with focus on the United States. It summarizes its development during three so called rounds, during which the quantitative easing has been used. This chapter also contains analysis of the entrance and exit strategy of the quantitative easing. In the third chapter, there is an econometric model estimated by ordinary least squares method with robust errors. This model is being used to verify the hypothesis whether the quantitative easing lowered long-term interest rates. The hypothesis has been rejected as the quantitative easing does not have statistically significant effect on any selected long-term bonds.

The thesis analyses problems of eurozone after the beginning of financial crisis in 2008, which continuously changed into economic and debt crisis. The thesis considers eurozone in aggregate and closer focuses on so called GIIPS (Greece, Ireland, Italy, Portugal, Spain) countries. Recent eurozone economic situation is compared to Japanese "lost decade" during 1990s, I seek for parallels and differences. Theoretical part shows approaches by economic schools to causes of cycle and to role of policymakers. Main challenges of fiscal and monetary policy are considered, specifically fiscal policy in time of high public indebtedness, monetary policy in liquidity trap etc. Applicative part considers causes of the economic situation at the beginning, more specifically devoted to balance sheets recession. Key part of the practical part it is analysis of applied fiscal and monetary policy, including helping efforts to financial system. Concluding remarks summarizes key understanding from the thesis, proposals are included and it is considered whether eurozone is going to follow Japanese path since 90's or not. It seems highly probable that eurozone is going to follow Japanese in terms of sluggish economic growth, parallels can be seen in weak impact of monetary policy in liquidity trap, but recommendations to fiscal policy from Japanese experience should be taken into account in very cautious way because of both specifics of eurozone and Japanese economy.

[pt] Quais devem ser a características da política monetária ótima sob comprometimento em uma situação de armadilha da liquidez global quando os Bancos Centrais não coordenam suas ações? Fazendo o uso de um modelo de economia aberta com dois países, fizemos um exercício numérico para endereçar essa questão e estudar as diferenças entre este caso e uma situação cooperativa, na qual as autoridades monetárias não estão somente preocupadas com a utilidade da população nacional, mas em vez disso maximizam uma medida de bem-estar global. Nossas descobertas apontam para diferenças nas características de dependência histórica e internacional da prescrição monetária em cada um dos casos observados. Também é feita uma análise de bem-estar do nosso experimento que sugere que um Banco Central local prefere, não só permanecer restrito pelo limite inferior zero da taxa de juros nominal por um período maior, mas também que o país estrangeiro saia dessa situação o quanto antes. Por fim, fazemos uma análise de robustez dos nossos resultados variando o tamanho de cada nação e o grau de substituição dos produtos produzidos em cada localidade. / [en] What should be the characteristics of the optimal monetary policy under commitment in the situation of a global liquidity trap when Central Banks do not coordinate their actions? Using a two-country open economy model, we perform a numerical exercise in order to address this question and study the differences between this setting and a cooperative situation, when monetary authorities are not only worried with the national household utility, but instead maximize a measure of world welfare. Our findings points towards differences of history and international dependence features of optimal monetary prescriptions in each of the observed cases. We also execute a welfare analysis of our experiment that suggests that a local Central Bank prefers, not only to stay restrained by zero lower bound (ZLB) on nominal interest rates for a longer period, but also that the foreign country exists this situation as early as possible. Lastly, we make a robustness analysis of our results varying the size of each nation and the degree of substitution of the composite goods produced in each locality.

The thesis deals with non-standard monetary policies of three central banks throughout the global financial crisis. The reason for using non-standard measures was also liquidity trap when monetary policy becomes ineffective. An important milestone was collapse of investment bank Lehman Brothers in September 2008. The central banks carried out some non-standard measures before the collapse such as the emergence of new or expanding existing facilities. However, after the collapse there was panic at the financial and capital markets and market interest rate spreads rose. Central banks were forced to respond to expanding its balance sheet and reducing the monetary policy rate to zero. The main reason for increasing total assets was securities purchases by central banks. The measure, which is expanding the balance sheet is called quantitative easing. In the thesis I try to describe and compare the non-standard measures (with a focus on quantitative easing) taken by the three central banks (Bank of England, the Fed and the ECB) and answer the question whether the measures are effective and whether they can replace the standard monetary policy.

Cette thèse étudie le choix des régimes de change dans des contextes économiques particuliers. La première partie (Chapitres 1 et 2) considère le cas des petits pays dont les dettes sont libellées en monnaies étrangères et celui d’une région constituée de tels petits pays lorsqu’il existe une similitude dans la composition des paniers définissant leurs taux de change effectifs. La deuxième partie de la thèse (Chapitres 3 et 4) se penche sur la considération des différents régimes de change dans le contexte monétaire de trappe à liquidité comparativement à un environnement monétaire traditionnel. En se basant sur une modélisation théorique de type DSGE, l’économétrie bayésienne et des données de panel, la thèse utilise principalement l’analyse des fonctions de réponses, de bien-être et de désalignements monétaires comme critères de comparaison de plusieurs régimes monétaires alternatifs. Les principaux enseignements de cette thèse se résument ainsi. Le change flexible semble être le meilleur régime pour des petites économies ouvertes comme ceux de l’Asie du Sud-Est. Au niveau régional, il est montré le ciblage effectif conduit à une stabilité des taux de change bilatéraux de la région, une sorte de fixité des taux de change qui ressemblerait à une zone monétaire de facto. Dans le contexte monétaire de trappe à liquidité, on trouve que,contrairement à la croyance commune lors la crise de la zone euro, l’union monétaire est plus performante que des politiques nationales de change flexible. Seule une intervention sur le taux de change nominal pourrait permettre au régime de change indépendant de dominer l’union monétaire. A travers une analyse théorique et empirique de l’effet de la trappe à liquidité sur l’ampleur des désalignements monétaires, il est aussi montré que la contrainte ZLB tend à réduire le désalignement monétaire dans une union monétaire comparativement aux politiques nationales de flottement.Cela plaide en faveur du renforcement de l’intégration monétaire au sein d’une union durant la période de trappe à liquidité. / This thesis investigates the choice of exchange rate regimes in specific economic contexts. The first part of this work (Chapters 1 and 2) considers the case of small open economies with foreign-currency denominated debt and that of a region where there is a similarity among trade-weighted currency baskets of countries. The second part of the thesis (Chapters 3 and 4) focuses on the study of exchange rate regimes and monetary integration in a liquidity trap environment relative to “tranquil” times. Based on dynamic stochastic general equilibrium (DSGE) models and Bayesian and Panel data econometrics, the thesis mainly uses the analyses of impulse responses, welfare and currency misalignments as comparison criteria among alternative currency regimes.The key lessons from this work are summarized as follows. For small open economies heavily in debted in foreign currency, like those of Southeast Asia, the flexible exchange is the best regime, followed by intermediate and fixed exchange rate regimes. At the regional level, it is shown that the exchange rate targeting regime leads to a stability of intra-regional bilateral exchange rates, which is a sort of fixity of exchange rates similar to a “de facto currency area”. In the context of a liquidity trap, we find that, contrary to common belief during the Euro area crisis, the currency union welfare dominates the independent floating regime. Only a central bank intervention in the form of a managed float policy could allow the independent floating to outperform the monetary union.Through both the empirical and theoretical analyses of the liquidity trap effects on currency misalignments, it is shown that the ZLB constraint tends to reduce currency misalignments compared with the independent floating policy. This suggests a reinforcement of the monetary integration within a monetary union during the liquidity trap