This article presents some recent theoretical and empirical contributions to the macroeconomic literature that challenge the perfect information hypo-thesis. By taking into account the information frictions encountered by economic agents, it is possible to explain some of the empirical regularities that are difficult to rationalise in the standard framework of full information rational expectations. As an example, we discuss how the sign, size and persistence of the estimated effects of monetary and fiscal policies can change when the informational frictions experienced by economic agents are taken into account.