Expectations and macroeconomics: learning and loose commitment

The three chapters of this thesis analyze different issues regarding the role of expectations in macroeconomics. The first two chapters consider that private economic agents can either be rational and forward looking or may actually need to use past data to learn how to form expectations. The first two chapters try to describe and estimate the different dynamics that these two types of expectation mechanisms induce. The third chapter analyzes the interaction between policy makers and forward-looking rational agents. The policy is time-inconsistent in such setting, leaving room for the debate between discretion and commitment. The third chapter analyzes optimal policy when the policy maker only defaults on past promises under certain conditions