The dissertation consists of three chapters. In the first chapter, I develop a model to study the production of private safe assets by the banking sector. In response to a shortage of safe assets, the banking sector produces more private safe assets which alleviate the decline of aggregate investment and output. However, producing more private safe assets exposes the bank to more aggregate risk. Macroprudential policies can adjust the production of private safe assets with a tradeoff: encouraging the production of private safe assets alleviates the safe asset shortage problem and improves output, at the cost of a more volatile economy. In the second chapter, I document that during the 2008 financial crisis, U.S. shadow banks deleveraged sharply while commercial banks maintained their leverage. I find that banks that relied more on short-term funding tended to deleverage more during the crisis. I build a model to incorporate both shadow banks and commercial banks with different leverage determination mechanisms. The model can explain the leverage dynamics of the banking sector and the flight-to-quality phenomenon observed in data. The third chapter is coauthored with Jianjun Miao and Pengfei Wang. We revisit Galí’s (2014) analysis by extending his model to incorporate persistent bubble shocks. We find that under adaptive learning, a stable bubbly steady state and the associated sunspot solutions under optimal monetary policy are not E-stable. When deriving the unique forward-looking minimum stable variable (MSV) solution around an unstable bubbly steady state, we obtain results that are consistent with the conventional views: leaning against the wind policy reduces bubble volatility and is optimal. Such a steady state and the associated MSV solution are E-stable.

京都大学 / 新制・課程博士 / 博士(経済学) / 甲第22950号 / 経博第625号 / 新制||経||294(附属図書館) / 京都大学大学院経済学研究科経済学専攻 / (主査)教授 柴田 章久, 准教授 高橋 修平, 教授 宇南山 卓 / 学位規則第4条第1項該当 / Doctor of Economics / Kyoto University / DGAM

Le premier chapitre questionne l'intuition conventionnelle selon laquelle une forte concentration au plus haut de la distribution des revenus devrait favoriser l'émergence de bulles d'actifs rationnelles. J'utilise un modèle OLG avec des fictions financières et des agents hétérogènes qui diffèrent en termes de taux d'épargne, portefeuilles d'actifs et talents. Je montre qu'une forte concentration promeut l'émergence de bulles si et seulement si ces bulles sont illiquides ou si tous les actifs offrent les mêmes rendements. A l'inverse, lorsque les bulles sont liquides et les actifs liquides paient une prime de liquidité, une faible concentration promeut l'émergence de bulles. Le deuxième papier étudie les conditions sous lesquelles une bulle d'actif augmente le PIB dans un modèle OLG-Nouveau Keynesien incluant le capital. Je montre que la stagnation séculaire est une condition nécessaire mais non suffisante. En effet, les bulles ne stimulent le PIB que si la demande agrégée est très fortement déficiente. Le troisième papier démontre que les modèle Nouveaux Keynesiens (NK) font des prédictions paradoxales lorsque la demande agrégée est chroniquement déficiente - un boom séculaire plutôt qu'une stagnation séculaire, et analyse comment ajuster ces modèles pour qu'ils deviennent viables dans l'environnement actuel. Je souligne l'importance cruciale des élasticités de l'offre et de la demande d'actifs par rapport au PIB à long terme ; j'effectue également une connexion entre le boom séculaire et d'autres prévisions paradoxales du modèle NK. / The first chapter questions the conventional intuition that a high concentration of income at the top of the distribution should promote the emergence of rational asset bubbles. I use an OLG model with financial fictions and heterogeneous agents that differ in terms of savings rate, portfolio choices and skills. I show that a high concentration at the top promotes the emergence of asset bubbles if and only if those asset bubbles are illiquid or financial markets are arbitrage-free. Instead, if asset bubbles are liquid and liquid assets pay a premium under illiquid assets, a low concentration promotes the emergence of asset bubbles. The second chapter studies the circumstances under which asset bubbles are expansionary in an OLG-New Keynesian that includes capital. I show that secular stagnation is a necessary but not sufficient condition. Indeed, asset bubbles stimulate investment, consumption and output if and only if there's a strong shortage of aggregate demand. Finally, the third paper shows that "standard" New Keynesian models make puzzling predictions when aggregate demand is chronically deficient they predict a secular boom, and seeks to understand how those models must be adjusted to analyze secular stagnation. I emphasize the crucial role of the long run elasticities of asset demand and supply with respect to the output gap in general equilibrium; and I also connect the secular boom to other puzzling predictions of the New Keynesian model.

This survey systematizes the rapidly growing literature on the influence of monetary policy and macroprudential policy on the macroeconomy. It examines the impact of monetary policy on the financial cycle and asks how macroprudential instruments influence the efficiency of monetary policy. The questions of whether monetary policy should take account of the financial cycle and lean against the wind is also addressed. The literature review shows that monetary policy is not neutral for financial stability, but should not take into account the financial cycle because the costs probably outweigh the benefits.

在很多資產泡沫的案例中，我們發現貨幣供給與信用皆伴隨資產價格飆漲而增加；但其通貨膨脹問題卻不嚴重。這似乎與傳統貨幣理論之概念─高貨幣成長刺激通膨─有所抵觸。我們推論在資產價格飆升時，民眾會增加其持有之貨幣以待適當時機購買資產，此種融通金融商品的貨幣即為俗稱之「游資」。游資增加將吸收部份貨幣擴張，因而減少最終流入商品市場的貨幣，緩和通貨膨漲。本論文建立一個Cash-in-Advance模型，發現當經濟體之貸款利率遠高於存款利率，及人民預期未來經濟持續進步時，確實可能發生上述現象。 / While some bubble economies, in which asset prices rise, experience exaggerated money and credit expansion, they often face merely moderate inflationary problems. It is likely that the increased money supply does not fully enter the commodity market and result in hyper-inflation; some of that increase may become investors’ money that waits for future investment opportunities and finally goes into the equity market. By utilizing a cash-in-advance model with a banking system and heterogeneous household expectations, this paper demonstrates the existence of this special phenomenon under the necessary condition by which, the loan rate is significantly higher than the deposit rate, and what the public believes in requires a persistent economic growth.

This study assess Prague real estate market from price level bubble existence point of view. For this purpose construct loglinear regression models for estimating price level of purchase and renting for several segments on the real estate market. These estimated price levels afterwards compare to theoretical price levels set by user cost concept, which employs fundamental factors such as capital costs, depreciation rates, personal income and property taxes, additional asset risk and expected capital gain. Study concludes that Prague real estate market does not currently experience positive price bubble, even one of the segments assess as underpriced.

Submitted by Murilo Resende Ferreira (muriloresende82@gmail.com) on 2014-10-28T15:22:42Z No. of bitstreams: 1 Tesedoutoradomuriloresende.PDF: 806113 bytes, checksum: e6d9cfcc660128de80d20f44f9c5213e (MD5) / Approved for entry into archive by BRUNA BARROS (bruna.barros@fgv.br) on 2014-11-10T11:34:49Z (GMT) No. of bitstreams: 1 Tesedoutoradomuriloresende.PDF: 806113 bytes, checksum: e6d9cfcc660128de80d20f44f9c5213e (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2014-11-13T13:40:01Z (GMT) No. of bitstreams: 1 Tesedoutoradomuriloresende.PDF: 806113 bytes, checksum: e6d9cfcc660128de80d20f44f9c5213e (MD5) / Made available in DSpace on 2014-11-13T13:40:15Z (GMT). No. of bitstreams: 1 Tesedoutoradomuriloresende.PDF: 806113 bytes, checksum: e6d9cfcc660128de80d20f44f9c5213e (MD5) Previous issue date: 2014-06-27 / This thesis contains two chapters, each one dealing with banking theory and the history of financiai arrangements. In Chapter 1, we extend a Diamond and Dybvig economy with imperfect monitoring of early withdrawals and make a welfare comparison between all possible allocations, as proposed by Prescott and Weinberg(2003) [37]. This imperfect monitoring is introduced by establishing indirect communication( trough a mean of payment) between the agents and the machine that is an aggregate of the financiai and the productive sector. The extension consists in studying allocations where a fraction of the agents can exploit imperfect monitoring and defraud the contracted arrangement by consuming more in the early period trough multiple means of payment. With limited punishment in the period of late consumption, this new allocation is called a separating allocation in contrast with pooling allocations where the agent with the ability of fraud is blocked from it by a costly mean of payment or by receiving enough future consumption to make fraud unattractive. The welfare comparison in the chosen range of parameters show that separating allocations are optimal for poor economies and pooling allocations for intermediary and rich ones. We end with a possible historical context for this kind of model, which connects with the historical narrative in chapter 2. In Chapter 2 we explore the quantitative properties of an early warning system for financiai crises based on the boom and bust framework described in more detail in appendix 1. The main variables are: real growth in equity and housing prices, the yield spread between the 10-year government bond and the 3-month interbank rate and the growth in total banking system assets. These variables display a higher degree of correct signals for recent crises (1984-2008) than comparable early warning systerns. Taking into account an increasing base-line risk ( due to increasing rates of credit expansion , lower interest rates and the accumulation of distortions) also proves to be informative and to help signaling crises in countries that did not go trough a great boom in previous years. / Esta tese contém dois capítulos, cada um lidando com a teoria e a história dos bancos e arranjos financeiros. No capítulo 1, busca-se extender uma economia Diamond-Dybvig com monitoramento imperfeito dos saques antecipados e realizar uma comparação do bem estar social em cada uma das alocações possíveis, como proposto em Presscott and Weinberg(2003). Esse monitoramento imperfeito é implementado a partir da comunicação indireta ( através de um meio de pagamento) entre os agentes e a máquina de depósitos e saques que é um agregado do setor produtivo e financeiro. A extensão consiste em estudar alocações onde uma fração dos agentes pode explorar o monitoramento imperfeito e fraudar a alocação contratada ao consumirem mais cedo além do limite, usando múltiplos meios de pagamento. Com a punição limitada no período de consumo tardio, essa nova alocação pode ser chamada de uma alocação separadora em contraste com as alocações agregadoras onde o agente com habilidade de fraudar é bloqueado por um meio de pagamento imune a fraude, mas custoso, ou por receber consumo futuro suficiente para tornar a fraude desinteressante. A comparação de bem estar na gama de parâmetros escolhida mostra que as alocações separadoras são ótimas para as economias com menor dotação e as agregadoras para as de nível intermediário e as ricas. O capítulo termina com um possível contexto histórico para o modelo, o qual se conecta com a narrativa histórica encontrada no capítulo 2. No capítulo 2 são exploradas as propriedade quantitativas de um sistema de previsão antecedente para crises financeiras, com as váriaveis sendo escolhidas a partir de um arcabouço de ``boom and bust'' descrito mais detalhadamente no apêndice 1. As principais variáveis são: o crescimento real nos preços de imóveis e ações, o diferencial entre os juros dos títulos governamentais de 10 anos e a taxa de 3 meses no mercado inter-bancário e o crescimento nos ativos totais do setor bancário. Essas variáveis produzem uma taxa mais elevada de sinais corretos para as crises bancárias recentes (1984-2008) do que os sistemas de indicadores antecedentes comparáveis. Levar em conta um risco de base crescente ( devido à tendência de acumulação de distorções no sistema de preços relativos em expansões anteriores) também provê informação e eleva o número de sinais corretos em países que não passaram por uma expansão creditícia e nos preços de ativos tão vigorosa.