On Targeting Frameworks And Optimal Monetary Policy

We show that speed limit policy, a monetary policy strategy that focuses on stabilizing inflation and the change in the output gap, consistently outperforms flexible inflation targeting and flexible price level targeting in empirical medium‐scale DSGE models under discretionary policymaking. In contrast to small‐scale New Keynesian models, this welfare ranking of the targeting frameworks is not overturned when inflation dynamics are mostly backward‐looking. Importantly, the performance of the speed limit policy shows less sensitivity to its parameterization than other frameworks that target the inflation rate or the price level.     

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.     

Lack of divine coincidence in New Keynesian models

The literature has long agreed that the divine coincidence holds in standard New Keynesian models: the monetary authority is able to simultaneously stabilize inflation and output gap in response to preference and technology shocks. I show that the divine coincidence holds only when inflation is stabilized at exactly zero. Even small deviations from zero generate policy trade-offs. I demonstrate this result using the model׳s non-linear equilibrium conditions to avoid biases from log-linearization. When the model is log-linearized, a non-zero steady state level of inflation gives rise to what I call the endogenous trend inflation cost-push shock in the New -Keynesian Phillips curve.     

Inflation targeting: What inflation rate to target?

In an economy with nominal rigidities in both an intermediate good sector and a finished good sector, and thus with a natural distinction between CPI and PPI inflation rates, a benevolent central bank faces a tradeoff between stabilizing the two measures of inflation, a final output gap and, unique to our model, a real marginal cost gap in the intermediate sector, so that optimal monetary policy is second-best. We discuss how to implement the optimal policy with minimal information requirement and evaluate the robustness of these simple rules when the central bank may not know the exact sources of shocks or nominal rigidities. A main finding is that a simple hybrid rule under which the short-term interest rate responds to CPI inflation and PPI inflation results in a welfare level close to the optimum, whereas policy rules that ignore PPI inflation or PPI sector shocks can result in significant welfare losses.     

FX Intervention in the New Keynesian Model

We develop an open-economy New Keynesian Model with foreign exchange (FX) intervention in the presence of a financial accelerator and shocks to risk appetite in international capital markets. We obtain closed-form solutions for optimal monetary and FX intervention policies assuming the central bank cannot commit to future policies, and we compare the solution to that under policy commitment. We show how FX intervention can help reduce the volatility of the exchange rate, of inflation, and of the output gap, thus mitigating welfare losses associated with shocks in the international capital markets. We also show that, when the financial accelerator is strong, there is a risk of indeterminacy (self-fulfilling currency and inflation movements) although FX intervention can reduce this risk and thus reinforce the credibility of the inflation targeting regime. Model simulations match well the impact of a VIX shock obtained by local projections on a panel of inflation targeting emerging markets.     

Monetary policy shocks, Choleski identification, and DNK models

A popular identifying assumption in structural VAR studies is that the monetary policy shock does not affect macroeconomic variables contemporaneously. We examine the consequences of using this identification strategy when the data-generating process is a basic Dynamic New Keynesian (DNK) model but without these assumed time delays. The principle conclusion is that the standard Choleski assumption can severely distort the impulse response functions, producing price puzzles and muted responses of inflation and the output gap to monetary shocks.     

Real Wage Rigidities and the New Keynesian Model

Most central banks perceive a trade-off between stabilizing inflation and stabilizing the gap between output and desired output. However, the standard new Keynesian framework implies no such trade-off. In that framework, stabilizing inflation is equivalent to stabilizing the welfare-relevant output gap. In this paper, we argue that this property of the new Keynesian framework, which we call the divine coincidence , is due to a special feature of the model: the absence of nontrivial real imperfections. We focus on one such real imperfection, namely, real wage rigidities. When the baseline new Keynesian model is extended to allow for real wage rigidities, the divine coincidence disappears, and central banks indeed face a trade-off between stabilizing inflation and stabilizing the welfare-relevant output gap. We show that not only does the extended model have more realistic normative implications, but it also has appealing positive properties. In particular, it provides a natural interpretation for the dynamic inflation–unemployment relation found in the data.     

Notes on the Underground: Monetary Policy in Resource‐Rich Economies

The central bank of a commodity‐exporting small open economy faces the traditional trade‐off between domestic inflation and output gap. The commodity sector introduces a terms‐of‐trade inefficiency that gives rise to an endogenous cost‐push shock, changes the target level for output, reduces the slope of the Phillips curve, and increases the importance of stabilizing the output gap. Optimal monetary policy calls for a reduction of the interest rate following a drop in the oil price. In contrast, a central bank with a mandate to stabilize consumer price inflation raises interest rates to limit the inflationary impact of an exchange rate depreciation.     

耐用品、投资专有冲击与货币政策福利

本文构建蕴含耐用品与非耐用品的两部门DSGE模型,研究投资专有冲击对货币政策及社会福利的影响。投资专有技术进步改进了投资转化为生产资本的效率,放大边际成本波动,增加了厂商调价动机和价格水平变动。即使耐用品价格完全灵活,最优货币政策也无法同时稳定价格和实际GDP。研究发现:(1)耐用品相对价格缺口波动率的上升虽然增加了实际GDP波动,但能够有效地降低投资专有技术对边际成本的冲击,减少价格变动的福利损失。所以两部门投资专有冲击时,央行倾向于稳定价格水平。与其相反,在单部门投资专有冲击和两部门生产技术冲击时,最优货币政策应降低耐用品相对价格缺口波动,稳定实际GDP。(2)对比三种泰勒规则:钉住非耐用品PPI、钉住加权平均PPI及钉住CPI,福利分析发现钉住非耐用品PPI最优,钉住CPI次之,钉住加权平均PPI的福利损失最大。就损失程度而言,投资专有冲击的福利损失是生产技术冲击的2倍,表明投资专有冲击加剧了最优货币政策在稳定价格与实际GDP间的权衡。     

Real Wage Rigidities and the New Keynesian Model

Most central banks perceive a trade‐off between stabilizing inflation and stabilizing the gap between output and desired output. However, the standard new Keynesian framework implies no such trade‐off. In that framework, stabilizing inflation is equivalent to stabilizing the welfare‐relevant output gap. In this paper, we argue that this property of the new Keynesian framework, which we call the divine coincidence, is due to a special feature of the model: the absence of nontrivial real imperfections. We focus on one such real imperfection, namely, real wage rigidities. When the baseline new Keynesian model is extended to allow for real wage rigidities, the divine coincidence disappears, and central banks indeed face a trade‐off between stabilizing inflation and stabilizing the welfare‐relevant output gap. We show that not only does the extended model have more realistic normative implications, but it also has appealing positive properties. In particular, it provides a natural interpretation for the dynamic inflation–unemployment relation found in the data.     

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.     

Optimal Monetary Policy in a Model with Agency Costs

This paper integrates a fully explicit model of agency costs into an otherwise standard Dynamic New Keynesian model in a particularly transparent way. A principal result is the characterization of agency costs as endogenous markup shocks in an output‐gap version of the Phillips curve. The model's utility‐based welfare criterion is derived explicitly and includes a measure of credit market tightness that we interpret as a risk premium. The paper also fully characterizes optimal monetary policy and provides conditions under which zero inflation is the optimal policy. Finally, optimal policy can be expressed as an inflation targeting criterion that (depending upon parameter values) can be either forward or backward looking.     

The Role of Inflation Target Adjustment in Stabilization Policy

How and under what circumstances can adjusting the inflation target serve as a stabilization-policy tool and contribute to welfare improvement? We answer these questions quantitatively with a standard New Keynesian model that includes cost-push-type shocks. Our proposed inflation target rule calls for the target to be adjusted in a persistent manner and in the opposite direction to the realization of a cost-push shock, which is essentially a makeup strategy. The inflation target rule, combined with a Taylor-type rule, significantly reduces inflation fluctuations originating from cost-push shocks and mitigates the stabilization trade-off, resulting in a similar level of welfare to that associated with the Ramsey optimal policy.     

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.     

Nominal GDP Targeting and the Taylor Rule on an Even Playing Field

Some economists advocate nominal GDP targeting as an alternative to the Taylor Rule. These arguments are largely based on the idea that nominal GDP targeting would require less knowledge on the part of policymakers than a traditional Taylor Rule. In particular, a nominal GDP targeting rule would not require real-time knowledge of the output gap. We examine the importance of this claim by amending a standard New Keynesian model to assume that the central bank has imperfect information about the output gap and therefore must forecast the output gap based on previous information. Forecast errors by the central bank can then potentially induce unanticipated changes in the short-term nominal interest rate, distinct from a standard monetary policy shock. We show that forecast errors of the output gap by the Federal Reserve can account for up to 13% of the fluctuations in the output gap. In addition, our simulations imply that a nominal GDP targeting rule would produce lower volatility in both inflation and the output gap in comparison with the Taylor Rule under imperfect information.     

Monetary Policy in a Forward-Looking Input–Output Economy

This paper examines the implications for monetary policy of sticky prices in both final and intermediate goods in a New Keynesian model. Both optimal policy under commitment and discretionary policy under simple loss functions are studied. Household utility losses under alternative loss functions are compared; additionally, the robustness of policy performance to model and shock misperceptions and parameter uncertainty is examined. Targeting inflation in both consumer and intermediate goods performs better than targeting inflation in one sector; targeting price levels of both final and intermediate goods performs significantly better. Moreover, targeting price levels in both sectors yields superior robustness properties.     

New Keynesian Macroeconomics and the Term Structure

This article complements the structural New Keynesian macro framework with a no-arbitrage affine term structure model. Whereas our methodology is general, we focus on an extended macro model with unobservable processes for the inflation target and the natural rate of output that are filtered from macro and term structure data. We find that term structure information helps generate large and significant parameters governing the monetary policy transmission mechanism. Our model also delivers strong contemporaneous responses of the entire term structure to various macroeconomic shocks. The inflation target shock dominates the variation in the "level factor" whereas monetary policy shocks dominate the variation in the "slope and curvature factors."     

Learning about the Term Structure and Optimal Rules for Inflation Targeting

In this paper, we incorporate the term structure of interest rates in the New Keynesian model and analyze optimal policy under uncertainty about private sector expectations and the degree of inflation persistence. The novel result of our paper is that for large deviations of inflation from its target, the active learning policy is less activist—in the sense of responding less aggressively to the state of the economy—than a myopic policy, which ignores the learning channel. Moreover, for most initial beliefs, the incentive for active learning increases as monetary policy’s leverage over the long‐term interest rate increases.     

New measures of the output gap based on the forward-looking new Keynesian Phillips curve

Forward-looking versions of the New Keynesian Phillips curve imply that the output gap, the deviation of the actual output from its natural level due to nominal rigidities, drives the dynamics of inflation relative to expected inflation. We exploit this to set up a bivariate unobserved component model for extracting new estimates of the output gap in the US. The gap estimates are large and persistent even after allowing for correlated trend and cycle shock. We then augment our model to use the information in the unemployment rate. The estimates confirm the presence of a large and persistent cyclical component.     

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.