This paper reviews recent research that grapples with the question: What happens after an exogenous shock to monetary policy? We argue that this question is interesting because it lies at the center of a particular approach to assessing the empirical plausibility of structural economic models that can be used to think about systematic changes in monetary policy institutions and rules. The literature has not yet converged on a particular set of assumptions for identifying the e®ects of an

more »

... us shock to monetary policy. Nevertheless, there is considerable agreement about the qualitative e®ects of a monetary policy shock in the sense that inference is robust across a large subset of the identi¯cation schemes that have been considered in the literature. We document the nature of this agreement as it pertains to key economic aggregates.