Optimal Policy Restrictions on Observable Outcomes

We study the restrictions implied by optimal policy DSGE models for the volatility of observable endogenous variables. Our approach uses a parametric family of singular models to discriminate which volatility sample outcomes have zero probability of being generated by an optimal policy. Thus the set of volatility outcomes generated by the model is not of measure zero even if there are no random deviations from optimal policymaking. This methodology is applied to a new Keynesian business cycle model widely used in the optimal monetary policy literature, and its implications for the assessment of US monetary policy performance over the 1984-2005 period are discussed.Optimal monetary policy, business cycle, DSGE model, policy performance

Vector Autoregressions and Reduced Form Representations of DSGE Models

Vector Autoreregression; Dynamic Stochastic General Equilibrium Model; Kalman Filter; Business Cycle Shocks

Openness and optimal monetary policy

We show that the composition of imports has important implications for the optimal volatility of the exchange rate. Using input-output data for 25 countries we document substantial differences in the import and non-tradable content of final demand components, and in the role played by imported inputs in domestic production. We build a business cycle model of a small open economy to discuss how the problem of the optimizing policy-maker changes endogenously as the composition of imports and of final demand is altered. Contrary to models where steady state trade openness is entirely characterized by home bias, we find that trade openness is a very poor proxy of the welfare impact of alternative monetary policies. Finally, we quantify the loss from an exchange rate peg relative to the Ramsey policy conditional on the composition of imports, using parameter values that are estimated from OECD input-output tables data. We find that the main determinant of the losses is the share of non-traded goods in final demand. JEL Classification: E52, E31, F02, F41Exchange Rate Regimes, international trade, Non-tradable Goods, Optimal Policy

Monetary policy, expected inflation and inflation risk premia

Within a New Keynesian business cycle model, we study variables that are normally unobservable but are very important for the conduct of monetary policy, namely expected inflation and inflation risk premia. We solve the model using a third-order approximation that allows us to study time-varying risk premia. Our model is consistent with rejection of the expectations hypothesis and the business-cycle behaviour of nominal interest rates in US data. We find that inflation risk premia are very small and display little volatility. Hence, monetary policy authorities can use the difference between nominal and real interest rates from index-linked bonds as a proxy for inflation expectations. Moreover, for short maturities current inflation is a good predictor of inflation risk premia. We also find that short-term real interest rates and expected inflation are significantly negatively correlated and that short-term real interest rates display greater volatility than expected inflation. These results are consistent with empirical studies that use survey data and index-linked bonds to obtain measures of expected inflation and real interest rates. Finally, we show that our economy is consistent with the Mundell-Tobin effect: increases in inflation are associated with higher nominal interest rates, but lower real interest rates.term structure of interest rates; monetary policy; expected inflation; inflation risk premia; Mundell-Tobin effect

Monetary policy and rejections of the expectations hypothesis

We study the rejection of the expectations hypothesis within a New Keynesian business cycle model. Earlier research has shown that the Lucas general equilibrium asset pricing model can account for neither sign nor magnitude of average risk premia in forward prices, and is unable to explain rejection of the expectations hypothesis. We show that a New Keynesian model with habit-formation preferences and a monetary policy feedback rule produces an upward-sloping average term structure of interest rates, procyclical interest rates, and countercyclical term spreads. In the model, as in U.S. data, inverted term structure predicts recessions. Most importantly, a New Keynesian model is able to account for rejections of the expectations hypothesis. Contrary to earlier work, we identify systematic monetary policy as a key factor behind this result. Rejection of the expectation hypothesis can be entirely explained by the volatility of just two real shocks which affect technology and preferences.term structure of interest rates; monetary policy; sticky prices; habit formation; expectations hypothesis

Monetary Policy and the Term Structure of Interest Rates

Term Structure of Interest Rates, Monetary Policy, Sticky Prices, Habit Formation, Expectations Hypothesis

Learning and optimal monetary policy

To conduct policy efficiently, central banks must use available data to infer, or learn, the relevant structural relationships in the economy. However, because a central bank's policy affects economic outcomes, the chosen policy may help or hinder its efforts to learn. This paper examines whether real-time learning allows a central bank to learn the economy's underlying structure and studies the impact that learning has on the performance of optimal policies under a variety of learning environments. Our main results are as follows. First, when monetary policy is formulated as an optimal discretionary targeting rule, we find that the rational expectations equilibrium and the optimal policy are real-time learnable. This result is robust to a range of assumptions concerning private sector learning behavior. Second, when policy is set with discretion, learning can lead to outcomes that are better than if the model parameters are known. Finally, if the private sector is learning, then unannounced changes to the policy regime, particularly changes to the inflation target, can raise policy loss considerably.Monetary policy

Welfare-based optimal monetary policy with unemployment and sticky prices: a linear-quadratic framework

In this paper, we derive a linear-quadratic model for monetary policy analysis that is consistent with sticky prices and search and matching frictions in the labor market. We show that the second-order approximation to the welfare of the representative agent depends on inflation and "gaps" that involve current and lagged unemployment. Our approximation makes explicit how the costs of fluctuations are generated by the presence of search frictions. These costs are distinct from the costs associated with relative price dispersion and fluctuations in consumption that appear in standard new Keynesian models. We use the model to analyze optimal monetary policy under commitment and discretion and to show that the structural characteristics of the labor market have important implications for optimal policy.Monetary policy ; Econometric models

The welfare consequences of monetary policy

We explore the distortions in business cycle models arising from inefficiencies in price setting and in the search process matching firms to unemployed workers, and the implications of these distortions for monetary policy. To this end, we characterize the tax instruments that would implement the first best equilibrium allocations and then examine the trade-offs faced by monetary policy when these tax instruments are unavailable. Our findings are that the welfare cost of search inefficiency can be large, but the incentive for policy to deviate from the inefficient flexible-price allocation is in general small. Sizable welfare gains are available if the steady state of the economy is inefficient, and these gains do not depend on the existence of an inefficient dispersion of wages. Finally, the gains from deviating from price stability are larger in economies with more volatile labor flows, as in the U.S.Labor market

The Welfare Consequences of Monetary Policy and the Role of the Labor Market: a Tax Interpretation

We explore the distortions in business cycle models arising from inefficiencies in price setting and in the search process matching firms to unemployed workers, and the implications of these distortions for monetary policy. To this end, we characterize the tax instruments that would implement the first best equilibrium allocations and then examine the trade-offs faced by monetary policy when tax instruments are unavailable. Our findings are that the welfare cost of search inefficiency can be large, but the incentive for policy to deviate from the inefficient flexible-price allocation is in general small. Sizable welfare gains are available if the steady state of the economy is inefficient, and these gains do not depend on the existence of an inefficient dispersion of wages. Finally, the gains from deviating from price stability are larger in economies with more volatile labor flows, as in the U.S.Optimal monetary policy, search inefficiency, job vacancies, unemployment