Forward-looking RE models such as the popular New Keynesian (NK) model do not provide a unique prediction about how the model economy behaves. We need some mechanism that ensures determinacy. McCallum (2011) says it is not needed because models are learnable only with the determinate solution...

A number of studies have found that news shocks account for a large part of the aggregate fl uctuations of the main macroeconomic variables.We show that when taking rational expectations into consideration there is a limit on the size of the variance of the news shocks,which has not been...

Forward-looking RE models such as the popular New Keynesian (NK) model do not provide a unique prediction about how the model economy behaves. We need some mechanism that ensures determinacy. McCallum (2011) says it is not needed because models are learnable only with the determinate solution...