Suite à la crise financière de 2007, les outils de politique monétaire conventionnelle se sont avérés insuffisants pour stabiliser l'économie et empêcher la diffusion de la crise financière. Les banques centrales ont de fait mis en place des politiques monétaires non conventionnelles. L’objectif de cette thèse est de participer à la compréhension théorique et empirique des politique monétaires non conventionnelles en concentrant nos efforts de modélisation sur la nature non-linéaire de la crise financière. Les deux premiers chapitres de cette thèse développent des modèles DSGE incorporant des contraintes de crédit occasionnellement saturées de manière à capturer la nature transitoire des phénomènes de crise. Dans le premier chapitre - obtenu dans un cadre d'économie fermée - un résultat notable est que les politiques d’assouplissement quantitatif diminuent bien l’amplitude de la crise, mais augmentent sa durée. Dans le deuxième chapitre, lorsque l’on implémente des programmes d’assouplissement quantitatif au niveau d'une union monétaire hétérogène constituée de deux pays, se pose le problème des hétérogénéités entre les pays membres de cette union. Nous trouvons qu’il est toujours plus intéressant pour la banque centrale de concentrer ses achats de titres dans les pays de l’union les plus touchés par la crise financière. De plus, un niveau intermédiaire d’intégration financière permet de minimiser les conséquences de la crise au niveau de l’union monétaire dans son ensemble. Dans le troisième chapitre, nous utilisons un modèle Markov-Switching VAR Bayésien pour comparer l’efficacité des politiques d’assouplissement quantitatif en période de crise et en période normale. Alors que les programmes d’assouplissement quantitatif sont particulièrement efficaces en période de crise, nous ne trouvons aucun effet significatif de ces programmes sur les variables macroéconomiques lorsque l'économie retourne à son état initial. / Following the 2007 financial crisis, conventional monetary policy tools prooved insufficient to stabilize the macroeconomy and to avoid a financial disruption. As a consequence, central banks relied more heavily on unconventional monetary policy tools. This thesis aims at contributing to the understanding of unconventional monetary policy tools, focusing on the inherently non-linear nature of financial crises. In the first two chapters, we use DSGE models with occasionally binding credit constraints to account for the transitory nature of financial disruption events. In chapter one, in the case of a closed economy, we find that quantitative easing decreases the magnitude of the crisis but increases its duration. Still, when looking for intertemporal effects of quantitative easing programs, it appears that they are always welfare improving. In chapter two, when implementing quantitative easing on a two country monetary union, comes the question of how to deal with heterogeneities between members. We find that it is always better to implement nationaly tailored quantitative easing programs. Finally, an intermediate degree of financial integration proves optimal to dampen the macroeconomic consequences of the financial crisis on the overall monetary union. In the third chapter, we use a Markov-Switching Bayesian VAR model to compare the efficiency of quantitative easing in normal times versus financial crisis times. While quantitative easing programs are highly efficient during financial crisis times, we find no significant effect of these programs when the economy goes back to normal times.

The aim of this thesis is to examine empirically the relationship between the exchange rate, the instruments of monetary policy and the measures of economic performance for Indonesia, Korea and Thailand during the pre- and post 1997 Asian financial crisis. The first core chapter (Chapter 2) assesses the possible linkages between the increase in domestic inflation and the exchange rate targeting policy adopted in these countries. Using the cointegration technique and a simple monetarist inflation model, Chapter 2 finds strong evidence that the exchange rate policy that generates a predominant domestic currency undervaluation has caused an increase in the domestic inflation rate for Indonesia and Korea. However, the exchange rate targeting policy that brings about a predominant baht overvaluation especially during the pre-crisis period has lowered Thailand’s inflation. Soon after the outbreak of 1997-crisis, instead of using the exchange rate as the nominal anchor, all three countries have implement their monetary policy around an inflation target following an inflation targeting framework. Owing to this significant structural break, the second core chapter (Chapter 3) uses a Markov-switching VAR framework to determine if the effects of monetary policy shocks have changed across different monetary policy regimes in these economies. Chapter 3 finds that regime switches occur in mid-1997 to 2000 for Indonesia, which coincides with the period after the onset of 1997-crisis and the economic recovery period; and in 1999 for Korea and Thailand, which coincides with the period when the inflation-targeting framework is adopted. From the regime-dependent impulse response functions, the responses of macroeconomic variables to monetary policy shocks have changed significantly across different regimes only for the case of Korea and Thailand. From the above discussions, Chapter 2 found that exchange rate targeting policy caused higher domestic inflation in Indonesia and Korea especially during the pre-crisis period; while Chapter 3 found that inflation targeting policy seemed to cause structural changes in Korea and Thailand. Therefore using a structural VAR framework, the third core chapter (Chapter 4) explores further the role of the exchange rate and inflation targeting policy on the economic performances of these economies during the pre- and post crisis periods. Chapter 4 finds that in the case of Indonesia and Korea, the foreign exchange market does create most of its own shocks during the pre-crisis period but not during the post crisis period. For Indonesia and Thailand, the soft US dollar peg policy during the pre-crisis period has caused additional distortions in the domestic economy. Moreover the role of the exchange rate as a shock absorber has increased during the post crisis period only for the case of Indonesia and Thailand. For all three economies, following the introduction of the inflation targeting policy, domestic short-term interest rates have been adjusted systematically to offset inflationary pressure following the real and nominal shocks. Moreover, in the case of Indonesia and Thailand, the unsystematic part of monetary policy plays a smaller role in explaining the variations in domestic economy during the post crisis period. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1320356 / Thesis (Ph.D.) -- University of Adelaide, School of Economics, 2008