Asset price bubbles and macroeconomic policies

Asset price bubbles have been affecting economies with ‘modern’ financial systems for at least 400 years. From the Dutch Tulip Mania to the Subprime bubble, passing by the South Sea bubble, the Japanese housing bubble or the Dot-Com bubble, the emergence of bubbles and their burst have marked financial markets and economies all around the world, and are often the cause of financial crises. In the light of the 2008 financial crisis, there is still some ambiguity on the measures that need to be adopted to deflate or limit the impact of these bubbles. Since bursting bubbles may lead to financial crises, it is crucial to make clarifications on their behaviours and policy recommendations on how to deal with asset price bubbles. My Thesis proposes an investigation of their existences, of their effects on the economy and analyses on the utilisation of monetary policy as an instrument to deflate bubbles, or at least, to limits their impact on economies. Chapter 1 starts with an overview on what are asset price bubbles and what do we know about them. Chapter 2 analyses the dynamic ownership of bubbles and their effects on the real activity and financial stability. Chapter 3 studies monetary policy in a New Keynesian model with an asset price bubble. Chapter 4 develops and estimates a DSGE model with stock market bubbles and nominal rigidities using Bayesian methods