[pt] Durante as últimas duas décadas, as economias do mundo têm sido caracterizadas por maior estabilidade na inflação e no produto. No entanto, aumentos na instabilidade financeira vêm preocupando os bancos centrais. Sendo assim, este trabalho tem como objetivo analisar empiricamente possíveis relações entre a política monetária brasileira e variações em preços de ativos, mais especificamente taxa de câmbio nominal e índice Bovespa. Os resultados encontrados para o período amostral de janeiro/2000 a janeiro/2006 sugerem que o modelo não-linear (TAR - threshold autoregressive) ajustase melhor aos dados brasileiros em comparação com o modelo linear e trazem indícios de que variações na taxa de câmbio nominal estão associadas a movimentos na taxa Selic em períodos mais conturbados da economia brasileira, os quais geram maior volatilidade no mercado financeiro. / [en] During the past two decades, world's economies have been characterized by stability on inflation and product levels. However, increases in financial instability are becoming a reason for concern to central banks. In this sense, the aim of this study is to analyze empirically possible relations between the Brazilian monetary policy and changes on asset prices, specifically the nominal exchange rate and the Bovespa index. The results for the sample between January, 2000 and January, 2006 suggest that the non-linear model, based on a Threshold Autoregressive model, fits better into Brazilian data than the linear model and find evidence that changes on nominal exchange rates and movements on Selic rate are associated during difficult times of the Brazilian economy, which are related to higher financial volatility.

Main goal of the diploma thesis is to research liquidity management problems of the Federal Reserve System during banking crisis 1929 -- 1933. Monetary policy implementation based on the implicit reserve targeting was not convenient in times of sharp expansion of the demand for reserves. FED was misled by Real-bills and Riefler-Burgess doctrine and considers monetary condition to be easy. Money interest rates responded very moderately to the shortage of the banking system's liquidity. We can find origin of the first quantitative easing in 1932 when FED first bought larger quantities of the government securities. Expansionary monetary policy during the banking crisis 1929 -- 1933 was also potentially limited by the conflict among U.S. financial stability and sustainability of the gold standard.