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.     

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.     

Monetary Policy and Inflation in the 70s

An influential paper by Clarida, Galí, and Gertler (2000) has attributed the great inflation of the 1970s to the violation of the Taylor principle in the conduct of U.S. monetary policy (weak, indeterminacy inducing response to expected inflation). We evaluate this thesis in the context of a standard New Keynesian model against a version of the model that incorporates incomplete information learning about the true state of the economy. The likelihood‐based estimation of the model overwhelmingly favors the specification with indeterminacy over the alternatives with determinacy, independent of the presence and size of misperceptions.     

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.     

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.     

Learnability and monetary policy: A global perspective

The recent literature on monetary policy design has emphasized the importance of equilibrium determinacy and learnability in the choice of policy rules. This paper contains an analysis of the learnability of the equilibrium in a class of simple, micro-founded models in which the policy authority uses a Taylor-type monetary policy rule. Unlike previous analyses, the model economy is not linearized about a steady state—instead, a global perspective is adopted. Globally, the nonlinear model economy can possess rational expectations equilibria other than the steady state consistent with the inflation target of the monetary authorities. These include a second, low inflation ‘liquidity trap’ steady state, periodic equilibria, and sunspot equilibria. The main results in the paper characterize the conditions under which these alternative equilibria maybe stable under adaptive learning, even when the policy rule obeys the Taylor principle. The stability of multiple equilibria is associated with policy rules which are forecast-based. An important finding is that backward-looking Taylor-type policy rules can guarantee that the unique learnable equilibrium is the steady state associated with the inflation target of the monetary authority.     

Optimal monetary policy under low trend inflation

In the monetary policy literature it is common to assume that trend inflation is zero, despite overwhelming evidence that zero inflation is neither empirically relevant nor a practical objective for central bank policy. We therefore extend the standard New Keynesian model to allow for positive trend inflation, showing that even low trend inflation has strong effects on optimal monetary policy and the dynamics of inflation, output and interest rates. Under discretion, the efficient policy deteriorates and there is no guarantee of determinacy. Even with commitment, targeting non-zero trend inflation leads to substantial welfare losses. Our results serve as a warning against indiscriminate use of models assuming zero trend inflation.     

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.     

Keynesian Inefficiency and Optimal Policy: A New Monetarist Approach

A simple model of monetary/labor search is constructed to study Keynesian indeterminacy and optimal policy. In the model, economic agents have trouble splitting the surplus from exchange appropriately, and we consider monetary and fiscal policies that correct this Keynesian inefficiency. A Taylor rule neither implies determinacy, nor does it support an efficient outcome. An optimal policy yields an efficient and determinate allocation of resources, but equilibrium policy actions, wages, and prices are indeterminate at the optimum.     

Monetary conservatism and fiscal policy

Does an inflation conservative central bank à la Rogoff (1985) remain desirable in a setting with endogenous fiscal policy? To provide an answer we study monetary and fiscal policy games without commitment in a dynamic, stochastic sticky-price economy with monopolistic distortions. Monetary policy determines nominal interest rates and fiscal policy provides public goods generating private utility. We find that lack of fiscal commitment gives rise to excessive public spending. The optimal inflation rate internalizing this distortion is positive, but lack of monetary commitment generates too much inflation. A conservative monetary authority thus remains desirable. When fiscal policy is determined before monetary policy each period, the monetary authority should focus exclusively on stabilizing inflation. Monetary conservatism then eliminates the steady state biases associated with lack of monetary and fiscal commitment and leads to stabilization policy that is close to optimal.     

Determinacy under Inflation Targeting Interest Rate Policy in a Sticky Price Model with Investment (and Labor Bargaining)

In a sticky price model with investment spending, recent research shows that inflation-forecast targeting interest rate policy makes determinacy of equilibrium essentially impossible. We examine a necessary and sufficient condition for determinacy under interest rate policy that responds to a weighted average of an inflation forecast and current inflation. This condition demonstrates that the average-inflation targeting policy ensures determinacy as long as both the response to average inflation and the relative weight of current inflation are large enough. We also find that interest rate policy that responds solely to past inflation guarantees determinacy when its response satisfies the Taylor principle and is not large. These results still hold even when wages and hours worked are determined by Nash bargaining.     

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.     

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.     

Real Balance Effects,Timing, and Equilibrium Determination

By assuming that money balances at the beginning instead of at the end of the period provide transaction services, standard results on nominal and real determinacy in monetary models are overturned. The key is that predetermined real money balances can be a state variable. Whereas the determination of the absolute price level typically depends on fiscal policy under an exogenous interest setting, nominal determinacy is now achieved even when fiscal policy is Ricardian. Also, in contrast to the Taylor principle, the interest rate policy should respond passively to changes in inflation, thus ensuring nonoscillatory and locally stable equilibrium sequences.     

Distortionary Taxation, Debt, and the Price Level

This paper compares the determinacy of equilibria under exogenous interest rates in an economy with a cash constraint, in which taxation is lump-sum or distortionary. Under passive fiscal policies lump-sum taxes generate nominal indeterminacy, while with distortionary taxes indeterminacy can be real, but not purely nominal. In general, under distortionary taxation uniqueness of the equilibrium allocation depends on monetary and fiscal policy interactions through taxes, debt, and interest rates. To illustrate this principle, we consider balanced-budget policies under distortionary income taxation and show that a unique equilibrium allocation prevails if interest rates are set consistent with long-run deflation. A separate section extends the analysis to endogenous interest rates.     

Spending Reversals and Fiscal Multipliers under an Interest Rate Peg

This paper examines whether fiscal stimuli are more effective when the monetary policy is less responsive to inflation. First, we provide empirical evidence suggesting that, in the period of U.S. passive monetary policy, a positive government spending shock was followed over time by a spending cut. Second, our theoretical analysis reveals that the pegged nominal interest rate is not a sufficient condition to generate a large fiscal multiplier. An increase in government spending could increase the long‐run real interest rate, if it is associated with a government spending reversal and a less responsive monetary policy. Consequently, the response of private consumption can be negative and the government spending multiplier is not necessarily greater than 1.     

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.     

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.     

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.     

Monetary Policy and Financial Markets at the Effective Lower Bound

I discuss what determines the effective lower bound (ELB) for the policy rate and argue that the ELB is not hard, but rather soft, and that it is probably slightly negative. I argue that, at the ELB, current output can be increased by (i) monetary policy that extends the period of credibly low policy rates and generates inflation expectations, (ii) financial‐stability policy—which is distinct from monetary policy—that reduces the spreads between market interest rates and the policy rate, and (iii) fiscal policy that increases the neutral real rate by reducing expected growth of government expenditure and increases potential output by increasing current government expenditure.