My dissertation is composed by three chapters that study monetary policy, international economics, and adaptive learning. The first and third chapters estimate New Keynesian DSGE models in order to examine the fear of floating phenomenon pervasive in emerging markets and the causes of the Great Inflation in the U.S. The first chapter estimates a small open economy model for the period after the 1994 crisis in Mexico. I find that the estimation of a Taylor rule for setting nominal interest rates favors a consistent response to the short-run nominal exchange rate post 1994. These results provide evidence that Mexico suffers from fear of floating. The second and the third chapters of my dissertation contribute to the studies of the implications of adaptive learning in monetary policy. The second chapter evaluates the desirability of policy rules that respond to wage inflation in a model with staggered price and wage setting in the context of determinacy and stability under adaptive learning. I find that, when the central bank responds to wage and price inflation and to the output gap a Taylor principle for wage and price inflation arises, but it is not necessarily related to stability under learning dynamics The third chapter proposed two potential channels through which monetary policy played a role in the Great Inflation. One approach holds that monetary policymakers during the 1970s preferred stabilizing output while post 1979 they preferred inflation stabilization. An alternative explanation contends that the Federal Reserve held misperceptions about the structure of the economy. The Great Inflation analysis incorporates policymakers that are learning adaptively and in that fashion, they form erroneous beliefs about the structure of the economy. The empirical results conclude that both channels are necessary to illustrate the role played by monetary policy in propagating and ending the Great Inflation. My dissertation results support Sargent's (1999) view that adaptive learning is a relevant mechanism affecting inflation policy.