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.     

Optimal monetary policy in a small open economy with staggered wage and price contracts

We study optimal monetary policy for a small open economy in a model where both domestic prices and wages are sticky due to staggered contracts. The simultaneous presence of the two forms of nominal rigidities introduces an additional trade-off between domestic inflation and the output gap. We derive a second-order approximation to the average welfare losses that can be expressed in terms of the unconditional variances of the output gap, domestic price inflation, and wage inflation. As a consequence, the optimal policy seeks to minimize a weighted average of these variances. We analyze welfare implications of several alternative simple policy rules, and find that domestic price inflation targeting generates relatively large welfare losses, whereas CPI inflation targeting performs nearly as well as the optimal rule.     

Monetary Policy Choices in Emerging Market Economies: The Case of High Productivity Growth

We develop a general equilibrium model of an emerging market economy where productivity growth differentials between tradable and non-tradable sectors result in an equilibrium appreciation of the real exchange rate—the so-called Balassa-Samuelson effect. The paper explores the dynamic properties of this economy and the welfare implications of alternative policy rules. We show that the real exchange rate appreciation limits the range of policy rules that, with a given probability, keep inflation and exchange rate within predetermined numerical targets. We also find that the B–S effect raises by an order of magnitude the welfare loss associated with policy rules that prescribe active exchange rate management.     

Optimal simple and implementable monetary and fiscal rules

Welfare-maximizing monetary- and fiscal-policy rules are studied in a model with sticky prices, money, and distortionary taxation. The Ramsey-optimal policy is used as a point of comparison. The main findings are: the size of the inflation coefficient in the interest-rate rule plays a minor role for welfare. It matters only insofar as it affects the determinacy of equilibrium. Optimal monetary policy features a muted response to output. Interest-rate rules that feature a positive response to output can lead to significant welfare losses. The welfare gains from interest-rate smoothing are negligible. Optimal fiscal policy is passive. The optimal monetary and fiscal rule combination attains virtually the same level of welfare as the Ramsey-optimal policy.     

Optimal monetary policy with the cost channel

In the standard new Keynesian framework, an optimizing policy maker does not face a trade-off between stabilizing the inflation rate and stabilizing the gap between actual output and output under flexible prices. An ad hoc, exogenous cost-push shock is typically added to the inflation equation to generate a meaningful policy problem. In this paper, we show that a cost-push shock arises endogenously when a cost channel for monetary policy is introduced into the new Keynesian model. A cost channel is present when firms’ marginal cost depends directly on the nominal rate of interest. Besides providing empirical evidence for a cost channel, we explore its implications for optimal monetary policy. We show that its presence alters the optimal policy problem in important ways. For example, both the output gap and inflation are allowed to fluctuate in response to productivity and demand shocks under optimal monetary policy.     

Inflation targeting and nominal-income-growth targeting: When and why are they suboptimal?

We compare optimal and simple interest-rate rules. Our model features optimizing agents, monopolistic competition in both product and labor markets, and one-period nominal contracts (for wages alone or for both wages and prices) signed before shocks are known. Exact solutions ensure that we obtain correct welfare rankings. Optimal rules maximize the unconditional expected utility of the representative agent with commitment subject to the information set of the policymaker. Even with monopolistic distortions, the optimal full-information rule makes the economy mimic the hypothetical full-flexibility equilibrium. Strict versions of inflation targeting, nominal-income-growth targeting, and other such simple rules are suboptimal under both full and partial information but flexible versions are optimal under certain partial-information assumptions. Nominal-income-growth targeting dominates inflation targeting for plausible parameter values.     

Price‐Level Targeting and Stabilization Policy

We construct a dynamic stochastic general equilibrium model to study optimal monetary stabilization policy. Prices are fully flexible and money is essential for trade. Our main result is that if the central bank pursues a price‐level target, it can control inflation expectations and improve welfare by stabilizing short‐run shocks to the economy. The optimal policy involves smoothing nominal interest rates that effectively smooths consumption across states.     

利率政策环境与央行货币政策选择

央行的货币政策实施受货币政策环境制约,特别是实施价格型货币政策时,在不同的利率环境下央行可能选择不同的利率调控模式。为此,通过构建门限回归模型对货币政策调控模式与利率区制的相依性进行实证检验,结果发现：在不同的利率区制内中央银行的政策偏好和利率调控模式存在显著差异。在高利率区制,中央银行存在针对产出缺口调整名义利率的政策偏好;在低利率区制,中央银行则不存在这种政策偏好,低利率环境下货币政策效应弱化甚至失效是导致此区制中央银行不针对产出缺口调整利率的主要原因。     

Optimal Monetary and Fiscal Policy with a Zero Bound on Nominal Interest Rates

I characterize optimal monetary and fiscal policy in a stochastic New Keynesian model when nominal interest rates may occasionally hit the zero lower bound. The benevolent policymaker controls the short‐term nominal interest rate and the level of government spending. Under discretionary policy, accounting for fiscal stabilization policy eliminates to a large extent the welfare losses associated with the presence of the zero bound. Under commitment, the gains associated with the use of the fiscal policy tool remain modest, even though fiscal stabilization policy is part of the optimal policy mix.     

Exact Utilities under Alternative Monetary Rules in a Simple Macro Model with Optimizing Agents

We construct an optimizing-agent model of a closed economy which is simple enough that we can use it to make exact utility calculations. There is a stabilization problem because there are one-period nominal contracts for wages, or prices, or both and shocks that are unknown at the time when contracts are signed. We evaluate alternative monetary policy rules using the utility function of the representative agent. Fully optimal policy can attain the Pareto-optimal equilibrium. Fully optimal policy is contrasted with both naive and sophisticated simple rules that involve, respectively, complete stabilization and optimal stabilization of one variable or a combination two variables. With wage contracts, outcomes depend crucially on whether there are also price contracts. For example, if labor supply is relatively inelastic, for productivity shocks, nominal income stabilization yields higher welfare when there are no price contracts. However, with price contracts, outcomes are independent of whether there are wage contracts, except, of course, for the nominal wage.     

An investigation of the gains from commitment in monetary policy

We propose a simple framework for analyzing a continuum of monetary policy rules characterized by differing degrees of credibility, in which commitment and discretion become special cases of what we call quasi-commitment. The monetary policy authority is assumed to formulate optimal commitment plans, to be tempted to renege on them, and to succumb to this temptation with a constant exogenous probability known to the private sector. By interpreting this probability as a continuous measure of the (lack of) credibility of the monetary policy authority, we investigate the welfare effect of a marginal increase in credibility. Our main finding is that, in a simple model of the monetary transmission mechanism, most of the gains from commitment accrue at relatively low levels of credibility.     

Optimal Monetary Policy with Countercyclical Credit Spreads

We study optimal monetary policy in a New‐Keynesian Dynamic Stochastic General Equilibrium (DSGE) model with a credit channel and relationship lending in banking. We show that borrowers' bank‐specific (deep) habits give rise to countercyclical credit spreads, which, in turn, make optimal monetary policy depart substantially from price stability, under both discretion and commitment. Our analysis shows that the welfare costs of setting monetary policy under discretion (with respect to the optimal Ramsey plan) and of using simpler suboptimal policy rules are strictly increasing in the magnitude of deep habits in credit markets and market power in banking.     

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.     

Trend inflation, wage and price rigidities, and productivity growth

What are the steady-state implications of inflation in a general-equilibrium model with real per capita output growth and staggered nominal price and wage contracts? Surprisingly, a benchmark calibration implies an optimal inflation rate of -1.9 percent. The analysis also shows that trend inflation has important effects on the economy when combined with nominal contracts and real output growth. Steady-state output and welfare losses are quantitatively important even for low values of trend inflation. Further, nominal wage contracting is found to be quantitatively more important than nominal price contracting in generating the results. This conclusion does not arise from price dispersion per se, but from an effect of nominal output growth on the optimal markup of monopolistically competitive labour suppliers. Finally, accounting for productivity growth is found to be important for calculating the welfare costs of inflation. Indeed, the presence of 2 percent productivity growth increases the welfare costs of inflation in the benchmark specification by a factor of four relative to the no-growth case.     

Quantifying and sustaining welfare gains from monetary commitment

Our objectives are: to quantify the stabilization welfare gains from commitment; to examine how commitment to an optimal rule can be sustained as an equilibrium; to find a simple interest rate rule that approximates the optimal commitment one. We utilize an empirical micro-founded euro-area DSGE model, a quadratic approximation of household utility as the welfare criterion, employing a nominal interest rate lower bound. In contrast to previous studies, we find significant commitment stabilization gains of around a 0.4-0.5% equivalent permanent consumption increase, and with higher price stickiness gains over 2%. We find that a simple optimized commitment rule responding to inflation and the real wage mimics the optimal one.     

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.     

The extensive margin and monetary policy

The creation of new firms, referred to as the extensive margin, is a significant but overlooked dimension of monetary policy. A monetary VAR documents that monetary policy has significant effects on firm creation. An analytically tractable model combining sticky prices and firm entry shows that entry alters the transmission of monetary policy innovations, acting much like a type of investment in more standard models. Monetary policy rules that offset the uncertainty of productivity shocks can raise the mean level of entry and thereby welfare, suggesting a new motivation for stabilization policy.     

Discretionary monetary policy and the zero lower bound on nominal interest rates

Ignoring the existence of the zero lower bound on nominal interest rates one considerably understates the value of monetary commitment in New Keynesian models. A stochastic forward-looking model with an occasionally binding lower bound, calibrated to the U.S. economy, suggests that low values for the natural rate of interest lead to sizeable output losses and deflation under discretionary monetary policy. The fall in output and deflation are much larger than in the case with policy commitment and do not show up at all if the model abstracts from the existence of the lower bound. The welfare losses of discretionary policy increase even further when inflation is partly determined by lagged inflation in the Phillips curve. These results emerge because private sector expectations and the discretionary policy response to these expectations reinforce each other and cause the lower bound to be reached much earlier than under commitment.     

Trend Inflation, Taylor Principle, and Indeterminacy

Positive trend inflation shrinks the determinacy region of a basic New Keynesian dynamic stochastic general equilibrium model when monetary policy is conducted by a contemporaneous interest rate rule. Neither the Taylor principle, which requires the inflation coefficient to be greater than one, nor the generalized Taylor principle, which requires that the nominal interest rate to be raised by more than the increase in inflation in the long run, is a sufficient condition for local determinacy of equilibrium. This finding holds for different types of Taylor rules, inertial policy rules, and price indexation schemes. Therefore, regardless of the theoretical setup, the monetary literature on interest rate rules cannot disregard average inflation in both theoretical and empirical analyses.     

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.