Suchergebnisse

We consider the desirability of modifying a standard Taylor rule for a central bank's interest rate policy to incorporate either an adjustment for changes in interest rate spreads (as proposed by Taylor [2008] and McCulley and Toloui [2008]) or a response to variations in the aggregate volume of credit (as proposed by Christiano et al. [2007]). We then examine how, under those adjustments, policy would respond to various types of economic disturbances, including those originating in the financial sector that increase equilibrium spreads and contract the supply of credit. We conduct our analysis using a simple DSGE model with credit frictions (Cúrdia and Woodford 2009), comparing the equilibrium responses to various disturbances under the modified Taylor rules with those under a policy that would maximize average expected utility. According to our model, a spread adjustment can improve on the standard Taylor rule, but the optimal size of the adjustment is unlikely to be as large as the one proposed, and the same type of adjustment is not desirable regardless of the source of variation in credit spreads. A response to credit is less likely to be helpful, and its desirable size (and even sign) is less robust to alternative assumptions about the nature and persistence of economic disturbances.

We extend the basic (representative-household) New Keynesian [NK] model of the monetary transmission mechanism to allow for a spread between the interest rate available to savers and borrowers, that can vary for either exogenous or endogenous reasons. We find that the mere existence of a positive average spread makes little quantitative difference for the predicted effects of particular policies. Variation in spreads over time is of greater significance, with consequences both for the equilibrium relation between the policy rate and aggregate expenditure and for the relation between real activity and inflation. Nonetheless, we find that the target criterion - a linear relation that should be maintained between the inflation rate and changes in the output gap - that characterizes optimal policy in the basic NK model continues to provide a good approximation to optimal policy, even in the presence of variations in credit spreads. We also consider a "spread-adjusted Taylor rule," in which the intercept of the Taylor rule is adjusted in proportion to changes in credit spreads. We show that while such an adjustment can improve upon an unadjusted Taylor rule, the optimal degree of adjustment is less than 100 percent; and even with the correct size of adjustment, such a rule of thumb remains inferior to the targeting rule.

This article examines how interest rates should have been changed in response to the commodity price shock and the credit crunch under different assumptions for the decision rules that might be used by central banks.