This dissertation contains three essays on Macroeconomics about the importance of information and expectations in the aggregate economy. The first chapter studies empirically and theoretically how the interest rate set by the central bank affect the economy through the effects that the announcement of the decisions has on people's forecasts of economic conditions. Using Brazilian Survey data that reports daily statistics, this chapter studies how forecasts of inflation and output growth respond to unexpected policy rate decisions. The results show that inflation forecasts increase in the short run after an unexpected increase in the policy rate and show a mild decrease 1 year after the meeting. Output forecasts, when measured by industrial ...