摘要：This article analyses the behavior of the Brazilian exchange rate (Real/US dollar) and the corresponding values forecasted by the market agents, from 2001 (November) to 2004 (may). We use the data-base of the Brazilian Central Bank, called Sistema de Expectativas de Mercado, which has been created in 1999. We evaluate the rational expectations hypothesis (REH) for the exchange rate market, comparing the mean value predicted by some Brazilian financial institutions with the daily exchange rate that has really occurred (PTAX). The particular arrangement of the data-base allows us to make the analysis in two different ways: with fixed-event forecasts. The main result suggests that the Brazilian exchange rate market support the weak form of the REH, for short horizons of forecasting.
其他摘要：This article analyses the behavior of the Brazilian exchange rate (Real/US dollar) and the corresponding values forecasted by the market agents, from 2001 (November) to 2004 (may). We use the data-base of the Brazilian Central Bank, called Sistema de Expectativas de Mercado, which has been created in 1999. We evaluate the rational expectations hypothesis (REH) for the exchange rate market, comparing the mean value predicted by some Brazilian financial institutions with the daily exchange rate that has really occurred (PTAX). The particular arrangement of the data-base allows us to make the analysis in two different ways: with fixed-event forecasts. The main result suggests that the Brazilian exchange rate market support the weak form of the REH, for short horizons of forecasting.
关键词：exchange rate;volatility;rational expectations;taxa de câmbio;volatilidade;expectativas racionais
