Optimal monetary policy with imperfect common knowledge

This paper determines optimal nominal demand policy in a flexible price economy in which firms pay limited attention to aggregate variables. Firms’ inattentiveness gives rise to idiosyncratic information errors and imperfect common knowledge about the shocks hitting the economy. This is shown to have strong implications for optimal nominal demand policy. In particular, if firms’ prices are strategic complements and economic shocks display little persistence, monetary policy has strong real effects, making it optimal to stabilize the output gap. Weak complementarities or sufficient shock persistence, however, cause price level stabilization to become increasingly optimal. With persistent shocks, optimal monetary policy shifts from output gap stabilization in initial periods following the shock to price level stabilization in later periods, potentially rationalizing the medium-term approach to price stability adopted by some central banks.     

Equilibrium Unemployment, Job Flows, and Inflation Dynamics

In order to explain the joint fluctuations of output, inflation and the labor market, this paper develops and estimates a general equilibrium model that integrates a theory of equilibrium unemployment into a monetary model with nominal price rigidities. The estimated model accounts for the responses of employment, hours per worker, job creation, and job destruction to a monetary policy shock. Moreover, search frictions in the labor market generate a lower elasticity of marginal costs with respect to output. This helps to explain the sluggishness of inflation and the persistence of output that are observed in the data.     

Data revisions and the identification of monetary policy shocks

Monetary policy research using time-series methods has been criticized for using more information than the Federal Reserve had available. To quantify the role of this criticism, we estimate VARs with real-time data while accounting for the latent nature of many economic variables, such as output. Our estimated monetary policy shocks are closely correlated with typically estimated measures. The impulse response functions are broadly similar across estimation methods. Our evidence suggests that the use of revised data in VAR analyses of monetary policy shocks may not be a serious limitation for recursively identified systems, but presents more challenges for simultaneous systems.     

Implications of habit formation for optimal monetary policy

We study the implications for optimal monetary policy of introducing habit formation in consumption into a general equilibrium model with sticky prices. Habit formation affects the model's endogenous dynamics through its effects on both aggregate demand and households’ supply of output. We show that the objective of monetary policy consistent with welfare maximization includes output stabilization, as well as inflation and output gap stabilization. We find that the variance of output increases under optimal policy, even though it acquires a higher implicit weight in the welfare function. We also find that a simple interest rate rule nearly achieves the welfare-optimal allocation, regardless of the degree of habit formation. In this rule, the optimal responses to inflation and the lagged interest rate are both declining in the size of the habit, although super-inertial policies remain optimal.     

Estimating Central Bank Preferences under Commitment and Discretion

This paper explains U.S. macroeconomic outcomes with an empirical New Keynesian model in which monetary policy minimizes the central bank’s loss function. The presence of expectations in the model forms a well‐known distinction between two modes of optimization, termed commitment and discretion. The model is estimated separately under each policy using maximum likelihood over the Volcker–Greenspan–Bernanke period. Comparisons of fit reveal that the data favor the specification with discretionary policy. Estimates of the loss function weights point to an excessive concern for interest rate smoothing in the commitment model but a more balanced concern relative to inflation and output stability in the discretionary model.     

The Value of Interest Rate Stabilization Policies When Agents Are Learning

We examine the expectational stability (E-stability) of rational expectations equilibrium in the "New Keynesian" model where monetary policy is optimally derived and interest rate stabilization is added to the central bank's traditional objectives of inflation and output stabilization. We consider both the case where the central bank lacks a commitment technology and the case of full commitment. We show that for both cases, optimal policy rules yield rational expectations equilibria that are E-stable for a wide range of empirically plausible parameter values. These findings stand in contrast to Evans and Honkapohja's findings for optimal monetary policy rules in environments where interest rate stabilization is not a central bank objective.     

Reconsidering the role of money for output, prices and interest rates

New Keynesian models of monetary policy downplay the role of monetary aggregates, in the sense that the level of output, prices, and interest rates can be determined without knowledge of the quantity of money. This paper evaluates the empirical validity of this prediction by studying the effects of shocks to monetary aggregates using a vector autoregression (VAR). Shocks to monetary aggregates are identified by the restrictions suggested by New Keynesian monetary models. Contrary to the theoretical predictions, shocks to broad monetary aggregates have substantial and persistent effects on output, prices and interest rates.     

The Interaction of Monetary and Macroprudential Policies

I analyze a New Keynesian dynamic stochastic general equilibrium (DSGE) model where the financing of productive investment is affected by a moral hazard problem. I solve for jointly Ramsey‐optimal monetary and macroprudential policies. I find that when a financial friction is present in addition to the standard nominal friction, the optimal policy can replicate the first‐best allocation if the social planner can conduct both monetary and macroprudential policy. Using monetary policy alone is not enough: a policy trade‐off between stabilizing inflation and output gap emerges. When policy follows simple rules, the source of fluctuations is relevant for the choice of the appropriate policy mix.     

Monetary policy and distribution

A segmented markets model of monetary policy is constructed, in which a novel feature is goods market segmentation, and its relationship to conventional asset market segmentation. The implications of the model for the response of prices, interest rates, consumption, labor supply, and output to monetary policy are determined. As well, optimal monetary policy is studied, as are the costs of inflation. The model features persistent nonneutralities of money, relative price effects of increases in the money supply, persistent liquidity effects, and a negative Fisher effect from a money supply increase. A Friedman rule is in general suboptimal.     

Optimal Fiscal Policy Rules in a Monetary Union

This paper investigates the importance of fiscal policy in providing macroeconomic stabilization in a monetary union. We use a microfounded New Keynesian model of a monetary union, which incorporates persistence in inflation and non-Ricardian consumers, and derive optimal simple rules for fiscal authorities. We find that fiscal policy can play an important role in reacting to inflation, output, and the terms of trade, but that not much is lost if national fiscal policy is restricted to react, on the one hand, to national differences in inflation and, on the other hand, to either national differences in output or changes in the terms of trade. However, welfare is reduced if national fiscal policy responds only to output, ignoring inflation.     

Money and macroeconomic performance: revisiting divisia money

Recent research suggests that the relation between money and the macroeconomy has sharply weakened in the U.S. after 1980. We reexamine this alleged breakdown by testing for cointegration between the macroeconomy and simple-sum and Divisia monetary aggregates. We check the robustness of our results by modeling multiple key breakpoints around the early 1980s. Unlike the case of simple-sum monetary aggregates, the evidence is overwhelming in its support for cointegration between Divisia money and macroeconomic variables, which persists despite several policy shifts and dramatic financial innovations in the post-1980 period. These results support Divisia money over simple-sum monetary aggregates as a guide in the implementation of monetary policy.     

Monetary policy transmission in vector autoregressions: A new approach using central bank communication

In this paper, we study the role played by central bank communication in monetary policy transmission. We employ the Swiss Economic Institute’s Monetary Policy Communicator to measure the future stance of the European Central Bank’s monetary policy. Our results indicate, first, that communication has an influence on inflation (expectations) similar to that of actual target rate changes. Communication also plays a noticeable role in the transmission of monetary policy to output. Consequently, future work on monetary policy transmission should incorporate both a short-term interest rate and a communication indicator. A second finding is that the monetary policy transmission mechanism changed during the financial crisis as the overall effect of monetary policy on (expected) inflation and output is weaker and of shorter duration during this period compared to the overall sample period.     

Habit formation and the persistence of monetary shocks

The dynamic effects and relative importance of monetary shocks in the US business cycle are studied using a sticky-price dynamic stochastic general equilibrium model with habit formation and capital adjustment costs. The model is estimated via maximum likelihood using data on output, real money balances, and the nominal interest rate. Econometric results indicate that the model has a strong internal propagation mechanism that can explain the persistent and hump-shaped response of US output and consumption to monetary shocks.     

Money and Output: Friedman and Schwartz Revisited

More than 50 years ago, Friedman and Schwartz examined historical data for the United States and found evidence of procyclical movements in the money stock, which led corresponding movements in output. We find similar correlations in more recent data; these appear most clearly when Divisia monetary aggregates are used in place of the Federal Reserve's official, simple‐sum measures. When we use information in Divisia money to estimate a structural vector autoregression, identified monetary policy shocks appear to have large and persistent effects on output and prices, with a lag that has lengthened considerably since the early 1980s.     

Maintaining low inflation: Money, interest rates, and policy stance

This paper presents a systematic empirical relationship between money and subsequent prices and output, using US, euro area and Swiss data since the 1960-1970s. Monetary developments, unlike interest rate stance measures, are shown to provide qualitative and quantitative information on subsequent inflation. The usefulness of monetary analysis is contrasted to weaknesses in modeling monetary policy and inflation with respectively short-term interest rates and real activity measures. The analysis sheds light on the recent change in inflation volatility and persistence as well as on the Phillips curve flattening, and reveals drawbacks in pursuing a low inflation target without considering monetary aggregates.     

The Interaction between Capital Requirements and Monetary Policy

The interaction between capital requirements and monetary policy is assessed by means of simple rules in a dynamic general equilibrium model featuring a banking sector. In “normal” times, when economic dynamics are driven by supply shocks, an active use of capital requirements generates modest benefits in terms of volatility of the target variables compared to the case in which only the central bank carries out stabilization policies. The lack of cooperation between the two policymakers may result in excessive volatility of the monetary policy rate and capital requirements. The benefits of introducing capital requirements become sizeable when financial shocks, which affect the supply of loans, are important drivers of economic dynamics; the availability of capital requirements as a policy tool yields a significant gain in terms of macroeconomic stabilization, regardless of the type of interaction between monetary and capital requirements policies.     

Can central banks’ monetary policy be described by a linear (augmented) Taylor rule or by a nonlinear rule?

The original Taylor rule establishes a simple linear relation between the interest rate, inflation and the output gap. An important extension to this rule is the assumption of a forward-looking behaviour of central banks. Now they are assumed to target expected inflation and output gap instead of current values of these variables. Using a forward-looking monetary policy reaction function, this paper analyses whether central banks’ monetary policy can indeed be described by a linear Taylor rule or, instead, by a nonlinear rule. It also analyses whether that rule can be augmented with a financial conditions index containing information from some asset prices and financial variables. The results indicate that the monetary behaviour of the European Central Bank and Bank of England is best described by a nonlinear rule, but the behaviour of the Federal Reserve of the United States can be well described by a linear Taylor rule. Our evidence also suggests that only the European Central Bank is reacting to financial conditions.     

Tax distortions and the case for price stability

We investigate the case for price stability in the general version of the New Keynesian (NNS) model with capital and several shocks. The model includes, in addition to the standard imperfect competition and monetary frictions, a non-trivial, endogenous tax distortion. We find that the case for perfect price stability is not significantly weakened. Optimal policy tolerates a small amount of output gap and price variability by reacting less strongly to supply and fiscal shocks in comparison to a policy that aims at perfect price stabilization.     

International dimensions of optimal monetary policy

This paper provides a baseline general equilibrium model of optimal monetary policy among interdependent economies with monopolistic firms and nominal rigidities. An inward-looking policy of domestic price stabilization is not optimal when firms’ markups are exposed to currency fluctuations. Such a policy raises exchange rate volatility, leading foreign exporters to charge higher prices vis-à-vis increased uncertainty in the export market. As higher import prices reduce the purchasing power of domestic consumers, optimal monetary rules trade off a larger domestic output gap against lower consumer prices. Optimal rules in a world Nash equilibrium lead to less exchange rate volatility relative to both inward-looking rules and discretionary policies, even when the latter do not suffer from any inflationary (or deflationary) bias. Gains from international monetary cooperation are related in a non-monotonic way to the degree of exchange rate pass-through.