Équilibre général | EPFL Graph Search

L'équilibre général est un concept d'économie qui désigne la possibilité pour les marchés d'atteindre l'équilibre simultanément par le libre jeu de l'offre et de la demande. L'équilibre général se distingue de l'équilibre simple (ou partiel) en ce qu'il s'agit d'un équilibre atteint sur l'intégralité des marchés. Issu de la microéconomie, la théorie de l'équilibre général a été développée par Léon Walras dans son ouvrage de , Éléments d'économie politique pure. Elle a atteint sa forme moderne avec les travaux de Kenneth Arrow et Gérard Debreu dans les années 1950. Concept Principes L'équilibre général est un concept issu de l'école néoclassique, quoiqu'il ait ensuite été discuté, et parfois repris, par différentes écoles de pensée. L'école néoclassique considère que le système économique est formé d'une multitude d'agents économiques (les ménages, les entreprises) qui échangent des biens afin de satisfaire leurs objectifs de maximisation de leur utilité. L'équi

Three Essays in Banking and Finance

Damien Olivier Klossner

This thesis develops three models that study the motivation of various agents to take on debt, and the impact that excessive financial leverage can have on social welfare. In the chapter "Short-term Bank Leverage and the Value of Liquid Reserves", the incentive of a bank to take on leverage stems from the fact that its short-term debt provides liquidity benefits to depositors, at the cost of exposing the bank to the risk of runs. In the model, a bank possesses two instruments to manage the risk of runs: its funding policy and the size of its liquid asset holdings, modeled as government bonds. Issuing more debt allows the bank to better capture the liquidity benefits fits priced into deposits but increases illiquidity risk. Holding more bonds makes the bank more robust to withdrawals but it reduces the bank's asset returns. When the supply is scarce, banks are the natural buyers of government bonds. This links the liquidity premium priced into government bonds to the risk of bank runs. In the chapter "Liquidity, Debt Overhang, and Monetary Policy", firms take on bank credit to relax their liquidity constraint and purchase new capital. But taking on debt creates a debt overhang distortion which causes entrepreneurs to pass on protable projects. In the model, entrepreneurs arrange for their financing before they observe the profitability of their investment opportunity. After the latter becomes known, entrepreneurs are liquidity-constrained when investment conditions are favorable, and over-indebted when they are unfavorable. The monetary authority can generate welfare gains by lowering the cost of holding liquidity and, when debt is contracted in nominal terms, by pursuing a counter-cyclical monetary policy. In the chapter "Safe Claim Production and Capital Structure", firms issue debt to satisfy the demand of risk-averse investors for safe claims, at the cost of increasing default risk. In general equilibrium, firms need to be compensated for this service, which can only occur if their debt and equity claims are held and priced by different investor types. This segmentation of the investor base can be sufficient to prevent the existence of a symmetric equilibrium. Instead, only a fraction of firms opt for levered capital structures, and the gain in value obtained by tranching cash flows into debt and equity is offset by the expected cost of default. Changes in aggregate leverage can be divided into variations in extensive (the fraction of levered firms ) and intensive (the leverage ratio of levered firms ) margins. Changes in rm business risk have opposite effects on leverage, depending on whether the risk is of a systematic nature or firm-specific nature.

EPFL2019

Essays in Information-Based Asset Pricing

Michael Hasler

I started my Ph.D. studies in the Fall 2008, a period ex-post perceived as being at the core of the Financial Crisis. At that time my ideas were vague and I struggled to find a good research topic. As surprising as it might appear, in one single week the discussions I had with my relatives provided me with enough ideas needed to write my thesis. Indeed, during that single week my relatives contacted me and complained about the fact that they had lost money invested in the financial market. They wanted me to advise them. I simply told them to invest their money in relatively safe bonds. My relatives did not realize how fruitful their behavior was for me. Indeed, after having advised them I wondered whether their willingness to gather information in bad times was optimal or pure irrationality. This issue is addressed in the first chapter of my thesis. The last two chapters investigate the impact of the willingness to gather more information in bad times than in good times on the dynamics of asset prices. My thesis answers two very important questions: When should investors acquire information given that information-processing is costly and what is the impact of the optimal information acquisition strategy on asset price dynamics? Consequently, the main topic of my thesis is the transmission of acquired information in financial markets. In the first chapter I consider a dynamic portfolio choice and costly information acquisition problem. Consistent with my relatives behavior, I show that it is optimal to gather more information in bad times than in good times. As the state of the economy worsens, investors optimally re-balance their portfolio towards safer investment and spend more and more money to gather more and more accurate information regarding future market moves. This result derived in a purely rational setup helps to understand the empirical observation that people tend to pay fluctuating attention to news, focusing more in downturns than in upturns. To the best of my knowledge, this paper is the first to consider costly information acquisition in a dynamic setting. The main contribution is to provide insights on how investors should optimally allocate their wealth to the financial market on the one hand and to information market on the other hand given current market conditions. In the second chapter (with Daniel Andrei) we model the optimal information acquisition strategy obtained in the first chapter in a general equilibrium framework and we show that this strategy (fluctuating attention paid to news) has very interesting implications on the dynamics of asset prices. Our main contribution is to highlight a J-shaped relationship between attention and volatility. By constructing an empirical measure of attention to news, we show that the theoretical prediction of our model holds in the data. Moreover, we are the first to provide a theoretical foundation for the fact that the slope of the term structure of equity premia is pro-cyclical. In the third chapter I investigate the impact of fluctuating attention to news in a multi-asset general equilibrium framework. My main contribution is to show that fluctuating attention to news generates return and volatility spillover effects among financial markets. As a bad shock hits one market, investors raise their attention to that particular market. This implies a simultaneous increase in each market volatility and in each cross-market correlation, a phenomenon called financial contagion. Moreover, I document that the interconnection between attention and uncertainty generates persistence in cross-market correlations. This very interesting result proves that persistence can be generated through Bayesian learning. Finally, I am the first to provide a theoretical foundation for the observed shape of the term structure of correlation. Consistent with empirical findings, I show that fluctuating attention implies an upward sloping term structure of correlation where the shorthand is wider than the longhand.

EPFL2013

Essays on asset pricing with preference heterogeneity

Giuliano Antonio Curatola

Investors' inheterogeneity is one of the prevailing features on financial markets. Thus, the recent asset pricing literature has produced a number of general equilibrium models where agents have different preferences. This thesis analyzes the effect of preference heterogeneity on financial markets in economies where agents have non-standard preferences for consumption: the first chapter is dedicated to loss-aversion and heterogeneity in the reference level of consumption; the second chapter describes an economy where agents follow fashions in consumption and differ in their fashion sensitivity; the third chapter considers the case of catching up with the Joneses preferences, heterogeneous risk aversion and long-run risk for consumption.

EPFL2013

Essays in Information-Based Asset Pricing

Michael Hasler

EPFL2013

Three Essays in Banking and Finance

Damien Olivier Klossner

EPFL2019