Endogenous Price Stickiness,Trend Inflation,and Macroeconomic Stability

Previous studies show that higher trend inflation is more likely to induce indeterminacy of equilibrium in sticky‐price models based on micro evidence that each period a fraction of prices is kept unchanged. This paper demonstrates that when the degree of price stickiness is endogenously determined in a Calvo model, indeterminacy caused by higher trend inflation is less likely. A key factor for determinacy is the long‐run inflation elasticity of output implied by the New Keynesian Phillips curve. This elasticity declines substantially with higher trend inflation in the case of exogenously given price stickiness, whereas in the case of endogenous price stickiness the decline in the elasticity is mitigated because higher trend inflation leads to a higher probability of price adjustment.     

Interest rate rules and price determinacy: The role of transactions services of bonds

Interest rate rules have been associated with price indeterminacy when they do not respond aggressively enough to inflation. Price indeterminacy is typically associated with indeterminacy of real bond balances, suggesting that the missing element is a meaningful role for government bonds. We assume that government bonds provide arbitrarily small transactions services and show that this can dramatically change the local and global determinacy conditions. In particular, the specification of fiscal policy affects the aggressiveness with which monetary policy must respond to inflation to deliver local determinacy—a range of passive monetary policies, even an interest rate peg, may yield determinacy.     

The Advantage of Flexible Targeting Rules

This paper investigates the consequences of debt stabilization for inflation targeting. If the fiscal authority holds constant the real value of debt at maturity under strict inflation targeting, the equilibrium dynamics are indeterminate for a wide range of parameters and steady‐state fiscal stances. “Flexible” targeting rules that include a concern for stabilization of the output gap can restore determinacy of the equilibrium. Flexible inflation targeting appears to be more robust than flexible debt targeting to alternative parameterizations. The fiscal authority can prevent indeterminacy under strict targeting rules by committing to hold constant debt net of interest rate spending.     

Using a long-term interest rate as the monetary policy instrument

Using a short-term interest rate as the monetary policy instrument can be problematic near its zero bound constraint. An alternative strategy is to use a long-term interest rate as the policy instrument. We find when Taylor-type policy rules are used by the central bank to set the long rate in a standard New Keynesian model, indeterminacy—that is, multiple rational expectations equilibria—may often result. However, a policy rule with a long-rate policy instrument that responds in a “forward-looking” fashion to inflation expectations can avoid the problem of indeterminacy.     

Determinacy and expectational stability of equilibrium in a monetary sticky-price model with Taylor rule

Recent studies show that the Taylor rule possesses desirable properties in terms of generating determinacy and E-stability of rational expectations equilibria under sticky prices. This paper examines whether this policy rule retains these properties within a discrete-time money-in-utility-function model, employing three timings of money balances of the utility function that the existing literature contains: end-of-period timing and two types of cash-in-advance timing. This paper shows: (i) even a small degree of non-separability of the utility function between consumption and real balances causes the Taylor rule to be much more likely to induce indeterminacy or E-instability if this rule responds not only to inflation but also to output or the output gap; (ii) differences among the three timings strongly alter conditions for the Taylor rule to ensure both determinacy and E-stability.     

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.     

What Asset Prices Should Be Targeted by a Central Bank?

This paper investigates the monetary policy design for restoring equilibrium determinacy. Our interests are whether a central bank should respond to asset price fluctuations, and if so, what asset prices should be targeted. We show that a monetary policy response to the price of a productive tangible asset (capital price) is helpful for equilibrium determinacy, while that to the price of an intangible asset that reflects a firm's profit (share prices) is a source of equilibrium indeterminacy. This result comes from the two assets' prices moving in opposite directions in response to a permanent increase in inflation.     

Determinacy and Learnability of Monetary Policy Rules in Small Open Economies

This paper evaluates under which conditions different Taylor-type rules lead to determinacy and expectational stability (E-stability) of rational expectations equilibrium in a simple "New Keynesian" small open economy model, developed by Gali and Monacelli (2005) . In particular, we extend Bullard and Mitra (2002) results of determinacy and E-stability in a closed economy to this small open economy framework. Our results highlight an important link between the Taylor principle and both determinacy and learnability of equilibrium in small open economies. More importantly, the degree of openness coupled with the nature of the policy rule adopted by the monetary authorities might change this link in important ways. A key finding is that, contrary to Bullard and Mitra, expectations-based rules that involve the consumer price inflation and/or the nominal exchange rate limit the region of E-stability and the Taylor Principle does not guarantee E-stability. We also show that some forms of managed exchange rate rules can help to alleviate problems of both indeterminacy and expectational instability, yet these rules might not be desirable since they can promote greater volatility in the economy.     

Inflation Band Targeting and Optimal Inflation Contracts

In this paper we provide a theoretical treatment of how inflation target ranges cope with the time-inconsistency problem arising from incentives for the monetary policymaker to exploit the short-run trade-off between employment and inflation to pursue short-run employment objectives, as in a Barro-Gordon (1983) model. Inflation band targets are able to achieve many of the benefits that arise under practically less attractive solutions such as the conservative central banker and optimal inflation contracts. Our theoretical model also shows how an inflation targeting range should be set and how it should respond to changes in the nature of shocks to the economy.     

The case for inflation stability

We evaluate the case for inflation stabilization in a New Keynesian (NNS) model that includes various frictions, capital accumulation and a variety of shocks. In such a model, price rigidity may provide the monetary authorities with an opportunity to improve upon the inefficient flexible price equilibrium via the suitable cyclical manipulation of real marginal costs. We find that such an opportunity is of limited value and that a strong case for perfect inflation stabilization remains. Policies that tolerate a small amount of inflation variability may outperform perfect inflation targeting when capital adjustment costs are low and the monetary distortion is substantial but only if prices are very flexible.     

Labor market search, the Taylor principle, and indeterminacy

In a sticky-price model with labor market search and matching frictions, forecast-based interest rate policy almost always induces indeterminacy when it is strictly inflation targeting and satisfies the Taylor principle. Indeterminacy is due to a vacancy channel of monetary policy that makes inflation expectations self-fulfilling. The effect of this channel strengthens as the sluggishness of the adjustment of employment relative to that of consumption increases. When this relative sluggishness is high, the Taylor principle fails to ensure determinacy, regardless of whether the policy is forecast-based or outcome-based, whether it is strictly or flexibly inflation targeting, or contains policy rate smoothing.     

Sticky Prices and Indeterminacy

The aim of this paper is to analyze the link between price rigidity and indeterminacy. This is done within a cash-in-advance economy that is known to exhibit indeterminacy at high degrees of relative risk aversion. My findings show that price stickiness reduces the scope of these sunspot equilibria: to be compatible with indeterminacy, sluggish price adjustment requires degrees of relative risk aversion that prove too high to square with data.     

Indeterminacy and Forecastability

Recent studies document the deteriorating performance of forecasting models during the Great Moderation, which conversely implies that forecastability was higher in the preceding era when the economy was unexpectedly volatile. We explain this phenomenon in the context of equilibrium indeterminacy in dynamic stochastic general equilibrium (DSGE) models. We first analytically show that a model under indeterminacy exhibits richer dynamics that can improve forecastability. Then, using a sticky‐price DSGE model, we numerically demonstrate that indeterminacy arising from passive monetary policy generates persistent dynamics that lead to superior forecastability. We also point out the possibility that forecastability under indeterminacy deteriorates when the degree of uncertainty about sunspot fluctuations is large.     

Optimal inflation persistence: Ramsey taxation with capital and habits

Ramsey models of fiscal and monetary policy featuring time-separable preferences and a fixed supply of capital predict highly volatile inflation with no serial correlation. In this paper, we show that an otherwise-standard Ramsey model that incorporates capital accumulation and habit persistence predicts highly persistent inflation. The result depends on increases in either the ability to smooth consumption or the preference for doing so. The effect operates through the Fisher relationship: a smoother profile of consumption implies a more persistent real interest rate, which in turn implies persistent optimal inflation. Our work complements a recent strand of the Ramsey literature based on models with nominal rigidities. In these latter models, inflation volatility is lower than in the baseline model but continues to exhibit little persistence. We quantify the effects of habit and capital on inflation persistence and also relate our findings to recent work on optimal fiscal policy with incomplete markets.     

Government Spending and the Taylor Principle

This paper explores how government size affects the scope for equilibrium indeterminacy in a New Keynesian economy, where part of the population live hand-to-mouth. The main result is that a higher level of public consumption is likely to generate indeterminacy and render the Taylor principle insufficient as criterion for equilibrium uniqueness. This holds even though fiscal policy serves to reduce swings in current income. Only if government consumption is a substitute for private consumption, will it narrow the scope for indeterminacy. Hence monetary policy should be conducted with an eye to the amount and composition of government consumption.     

货币超发是中国通货膨胀的根源吗?——基于DSGE模型不确定均衡解的分析

本文构建了一个充分反映中国宏观经济结构和体制特征的DSGE模型,并用贝叶斯估计方法对模型进行了估计和分析。我们发现,中国宏观经济存在非确定均衡解,自我实现的通胀预期对中国通货膨胀和产出波动有显著的影响,逆向供给冲击是近年来中国通货膨胀的主要原因。通过反事实模拟方法,我们发现近年来我国央行实施的实际货币政策基本符合最优货币政策,我们还估算中国货币增长长期目标的适度水平为18%左右,过高或过低的货币增长率都会加大消费和通货膨胀的波动,并降低社会的长期福利水平。     

Inflation dynamics: A cross-country investigation

We document that “persistent and lagged” inflation (with respect to output) is a world-wide phenomenon in that these short-run inflation dynamics are highly synchronized across countries. In particular, the average cross-country correlation of inflation is significantly and systematically stronger than that of output, while the cross-country correlation of money growth is essentially zero. We investigate whether standard monetary models driven by monetary shocks are consistent with the empirical facts. We find that neither the new Keynesian sticky-price model nor the sticky-information model can fully explain the data. An independent contribution of the paper is to provide a simple solution technique for solving general equilibrium models with sticky information.     

The New Keynesian Phillips Curve: From Sticky Inflation to Sticky Prices

The New Keynesian Phillips Curve (NKPC) model of inflation dynamics based on forward-looking expectations is of great theoretical significance in monetary policy analysis. Empirical studies, however, often find that backward-looking inflation inertia dominates the dynamics of the short-run aggregate supply curve. This inconsistency is examined by investigating multiple structural changes in the NKPC for the U.S. between 1960 and 2005, employing both inflation expectations survey data and a rational expectations approximation. We find that forward-looking behavior plays a smaller role during the high and volatile inflation regime to 1981 than in the subsequent period of moderate inflation, providing empirical support for sticky price models over the last two decades. A break in the intercept of the NKPC is also identified around 2001 and this may be associated with U.S. monetary policy in that period.     

A quantitative exploration of the opportunistic approach to disinflation

Under a conventional policy rule, a central bank adjusts its policy rate linearly according to the gap between inflation and its target, and the gap between output and its potential. Under “the opportunistic approach to disinflation” a central bank controls inflation aggressively when inflation is far from its target, but concentrates more on output stabilization when inflation is close to its target, allowing supply shocks and unforeseen fluctuations in aggregate demand to move inflation within a certain band. We use stochastic simulations of a small-scale rational expectations model to contrast the behavior of output and inflation under opportunistic and linear rules.     

Aggregate Stability and Balanced‐Budget Rules

It has been shown that under perfect competition and a Cobb‐Douglas production function, a basic real business cycle model may exhibit indeterminacy and sunspot fluctuations when income tax rates are determined by a balanced‐budget rule (BBR). This paper introduces in an otherwise standard real business cycle model a more general and data‐coherent class of production functions, namely, a constant elasticity of substitution production function. We show that the degree of substitutability between production factors is a key ingredient to understanding the (de)stabilizing properties of a BBR. Then we calibrate the model consistently with the empirical evidence; that is, we set the elasticity of substitution between labor and capital below unity. We show that compared to the Cobb‐Douglas case, the likelihood of indeterminacy under a BBR is greatly reduced in the U.S., the EU, and the UK.