We also consider asymmetric effects that are implied by models with menu costs (see, among others, Romer, 1990, andMankiw, 1994). In static (deterministic) settings, standard menu-cost models imply that "big" monetary policy shocks are neutral because firms would find it optimal to adjust nominal prices, while "small" monetary policy shocks would have real effects because keeping nominal prices fixed is associated with only a second-order cost. In other words, the firms have to decide-before the monetary policy shock is observed-whether to index their prices (at the cost of paying the menu cost) or not. Firms will choose indexation (which implies neutrality) only if the variance of monetary policy shocks is high. We extend the analysis by assuming that the monetary policy process can change between having a "high" variance and a "low" variance. This approach allows for identifying periods of neutrality and periods of non-neutrality.Finally, we consider the case in which only small
Asymmetric Effects of Monetary Policy in the United StatesMorten O. Ravn and Martin Sola T his paper tests for the presence of asymmetric effects of monetary policy on aggregate activity using U.S. postwar quarterly data. We are interested in three types of asymmetry: (i) whether negative and positive monetary policy shocks have different effects on output; (ii) whether big or small shocks have different effects; and/or (iii) whether low-variance, negative shocks have asymmetric effects on output. We discuss the three possibilities below and explain under which conditions these asymmetries might take place. 1 To date, the empirical literature has focused on a particular asymmetry that we call "the traditional Keynesian asymmetry," which states that positive monetary policy shocks have smaller real effects than negative monetary policy shocks-or, in a more extreme form, that only the latter shocks have real effects. This asymmetry can be derived under the assumption of either downward (upward) sticky (flexible) nominal wages or sticky prices together with rationing of demand. 2,3 S E P T E M B E R / O C TO B E R 2 0 0 4 4 1 1 Other types of asymmetric effects have been explored by Garcia and Schaller (1995), who examine whether monetary policy affects output differently in different phases of the business cycle, and Ravn and Sola (1997), who look at the effects of monetary policy on transitional dynamics. Hooker and Knetter (1996) analyze whether military procurement spending has asymmetric effects on employment, and they find that "big" negative shocks to procurement have proportionally larger effects on employment growth than large positive shocks or small shocks to procurement. Hooker (1996) examines whether there are asymmetries in the relationship between oil-price shocks and U.S. macroeconomic variables. He finds that the asymmetric effects in this relationship are fragile. Here we focus on the relationship between monetary policy shocks and aggregate activity. Lo and Piger (2003) examine regime switching in the response of U.S....