Abstract : Recognizing the importance of the exchange rate system for open economies, we study the macroeconomic effects of exchange rate regimes. In the first chapter, we define the exchange rate regime and discuss the official or de jure classification of exchange regimes by the International Monetary Fund (IMF) as well as de facto classifications developed by Levy Yeyati and Sturzenegger (2005) and by Reinhart and Rogoff (2003). We subsequently discuss the question of which classification(s) of regimes to use. In the second chapter, the impact of exchange rate regimes on growth volatility is investigated. Building on the literature on the relationships between the exchange rate arrangement and volatility and the literature on the determinants of growth volatility, the objective is to know whether the exchange rate system affects growth volatility once the determinants of volatility identified by the existing literature are controlled for. The chapter also assesses the channels through which the exchange rate regime affects volatility. In particular, we ask whether the contribution of terms of trade instability to growth volatility is influenced by the exchange rate arrangement. Is the impact of the exchange rate regime on volatility affected by financial and economic development ? Volatility or instability is measured from a trend which process is obtained from panel unit root tests. By using de jure exchange rate regimes along with de facto ones as classified by Reinhart et Rogoff (2003), we are able to assess the sensitivity of the results to the classification of exchange regimes. In the third chapter, the analysis is taken a step further by investigating whether the relation between growth and volatility is modified by the exchange rate system. Does the exchange rate regime modify the direct impact of volatility on growth ? In other words, does a given level of volatility reduces output growth identically under fixed and flexible regimes ? Moreover, are the indirect effects of volatility on the growth rate of per capita real output modified by the exchange rate system ? To answer the latter question, the channels of investment, human capital, trade and financial development are considered. Another objective of the chapter is to verify whether the effects of exchange rate regimes and volatility on output growth are heterogeneous or not according to the very quantiles of output growth. To pursue this avenue, we use the technique of regression quantiles with instrumental variables. In the fourth chapter, the impact of the exchange rate arrangement on the economy's adjustment is analyzed. Does the adjustment of the economy – measured by real exchange rate misalignment – depend on the exchange rate regime ? Is the impact of the exchange rate system on misalignment explained by its effects on real overvaluation and undervaluation episodes ? What do de jure and de facto exchange rate regimes, and deviations of announced from observed exchange rate policies reveal ? To answer these questions, we follow two steps. In the first one, a cointegration relation between the real exchange rate and its real and nominal determinants is estimated using non stationary panel techniques (Pedroni, 1996, 2000 and 2004) in the samples of low income, middle income and high income countries. Misalignment is then obtained as the deviation of the actual real exchange rate from its equilibrium value, the latter being determined by the equilibrium values of the fundamentals. In the second step, the impact of the exchange rate regime on the economy's adjustment is assessed using the measure of real exchange rate misalignment computed in the first step.