Optimal Commitment Policy Research Articles

Inattention and the Taxation Bias

Abstract This paper shows that inattention to taxes generates a time-inconsistency problem in the choice of tax policy, leading to higher taxes in equilibrium. These discretionary tax increases are inefficient as they are deviations from the socially optimal commitment policy. We call these deviations a taxation bias. Combining sufficient statistics and structural approaches, we quantify the magnitude of this policy distortion for the U.S. redistributive tax-transfer system. We find that the taxation bias ranges between 3 and 8 percentage points, alters tax-transfer progressivity, and has significant welfare effects. Overall, our findings shed new light on the implications of inattention and misperceptions.

Credible Forward Guidance

How can the central bank credibly implement a “lower-for-longer” strategy? To answer this question, we analyze a series of optimal sustainable policy problems—indexed by the duration of reputational loss—in a sticky-price model with an effective lower bound (ELB) constraint on nominal interest rates. We find that, even when the central bank lacks commitment, the central bank can still credibly keep the policy rate at the ELB for an extended period—though not as extended as under the optimal commitment policy—and meaningfully mitigate the adverse effects of the ELB constraint on economic activity.

Credible Forward Guidance

We analyze credible forward guidance policies in a sticky-price model with an effective lower bound (ELB) constraint on nominal interest rates by solving a series of optimal sustainable policy problems indexed by the duration of reputational loss. Lower-for-longer policies---while effective in stimulating the economy at the ELB---are potentially time-inconsistent, as the associated overheating of the economy in the aftermath of a crisis is undesirable ex post. However, if reneging on a lower-for-longer promise leads to a loss of reputation and prevents the central bank from effectively using lower-for-longer policies in future crises, these policies can be time-consistent. We find that, even without an explicit commitment technology, the central bank can still credibly keep the policy rate at the ELB for an extended period---though not as extended under the optimal commitment policy---and meaningfully mitigate the adverse effects of the ELB constraint on economy activit y.

A Promised Value Approach to Optimal Monetary Policy*

AbstractThis paper characterizes optimal commitment policy in the New Keynesian model using a recursive formulation of the central bank's infinite‐horizon optimization problem in which promised inflation and output gap – as opposed to lagged Lagrange multipliers – act as pseudo‐state variables. Our recursive formulation is motivated by (Kydland, F. and Prescott, E. C. (1980). Journal of Economic Dynamics and Control Vol. 2, pp. 79–91). Using three well‐known variants of the model – one featuring inflation bias, one featuring stabilization bias and one featuring a lower bound constraint on nominal interest rates – we show that the proposed formulation sheds new light on the nature of the intertemporal trade‐off facing the central bank.

Output hysteresis and optimal monetary policy

We derive a fully quadratic approximation to welfare under endogenous growth and study optimal monetary policy. Away from the ZLB, optimal commitment policy sets interest rates to eliminate output hysteresis. A strict inflation targeting rule implements the optimal policy. At the ZLB, strict inflation targeting is sub-optimal and admits output hysteresis, defined as a permanent loss in potential output. A new policy rule that targets output hysteresis returns the output to the pre-shock trend and approximates the welfare gains under optimal commitment policy. A central bank unable to commit to future policy actions suffers from hysteresis bias: it does not offset past losses in potential output.

The amplification of the New Keynesian models and robust optimal monetary policy

This paper analyzes whether and how model uncertainty affects the amplification mechanism of the New Keynesian models in a simple min-max framework where the central bank plays a zero-sum game versus a hypothetical, evil agent. A first finding on a benchmark model with staggered price setting is that a robust optimal commitment policy necessitates more aggressive policy under a demand shock. Further, bringing additional persistence into the model deteriorates the effectiveness of monetary policy. Hence, allowing for either habit formation or partial indexation of prices to lagged inflation rate requires a stronger response for the policy to a demand shock. Together with the specification doubts, in order to reassure the private sector and signal that it will stabilize the fluctuations in the output gap, the policymaker reacts more aggressively as persistence rises. Although inflation persistence does not change the impact of model uncertainty, habit formation in consumption eliminates even reverses the impact of uncertainty on the policy reaction to a supply shock. In all cases, policymaker attributes less importance to nominal interest rate inertia with concerns about model uncertainty.

News shocks modeling on monetary policies using dynamic stochastic general equilibrium (DSGE) model

PurposeThe purpose of this paper is to investigate the effects of news shocks on monetary policies using the dynamic stochastic general equilibrium (DSGE) model. To this end, two kinds of news shocks (known as technology and consumer preferences) are defined according to Khan and Tsoukalas’ (2012) approach.Design/methodology/approachIn order to construct and simulate the DSGE model to approaching the real conditions in a case study, consumption habits in the utility function were concerned based on the assumption of the zero-value obtained from multiplying the inflation by the real interest rate in the Fisher’s equation, whereas the real interest rates in the long run were appointed as negative remark in simulating the monetary policy models. The estimation and simulation results for the research models indicated that monetary policies using the interest rate instrument identified the news shocks less frequently than monetary policies using the monetary base instrument.FindingsThe approximate value of the social loss function in the optimal commitment and discretionary monetary policies suggests that the optimal commitment policy is estimated to be lower in both cases. Due to value of the social loss function in optimal monetary policies with nominal interest rate instrument in the presence of news shocks, this could be claimed that monetary policy with interest rate instrument is more appropriate than the monetary policy with a monetary base instrument.Originality/valueThe approximate value of the social loss function in the optimal commitment and discretionary monetary policies suggests that the optimal commitment policy is estimated to be lower in both cases.

Credible Forward Guidance

We analyze credible forward guidance policies in a sticky-price model with an effective lower bound (ELB) constraint on nominal interest rates by solving a series of optimal sustainable policy problems indexed by the duration of reputational loss. Lower-for-longer policies---while effective in stimulating the economy at the ELB---are potentially time-inconsistent, as the associated overheating of the economy in the aftermath of a crisis is undesirable ex post. However, if reneging on a lower-for-longer promise leads to a loss of reputation and prevents the central bank from effectively using lower-for-longer policies in future crises, these policies can be time-consistent. We find that, even without an explicit commitment technology, the central bank can still credibly keep the policy rate at the ELB for an extended period---though not as extended under the optimal commitment policy---and meaningfully mitigate the adverse effects of the ELB constraint on economy activit y.

Role of Expectations in a Liquidity Trap

A number of previous studies suggest that inflation expectations are important in considering the effectiveness of monetary policy in a liquidity trap. However, the role of inflation expectations can be very different, depending on the type of monetary policy that a central bank implements. This paper reveals how a private agent forms inflation expectation affects the effectiveness of monetary policy under the optimal commitment policy, the Taylor rule, and a simple rule with price-level targeting. We examine two expectation formations: (i) different degrees of anchoring, and (ii) different degrees of forward-lookingness. We show that how to form inflation expectations is less relevant when a central bank implements the optimal commitment policy, while it is critical when the central bank adopts the Taylor rule or a simple rule with price-level targeting. Even for the Japanese economy, the effects of monetary policy on economic dynamics significantly change according to expectation formations under rules other than the optimal commitment policy.

Role of expectations in a liquidity trap

A number of previous studies suggest that inflation expectations are important in considering the effectiveness of monetary policy in a liquidity trap. However, the role of inflation expectations can be very different, depending on the type of monetary policy that a central bank implements. This paper reveals how a private agent forms inflation expectation affects the effectiveness of monetary policy under the optimal commitment policy, the Taylor rule, and a simple rule with price-level targeting. We examine two expectation formations: (i) different degrees of anchoring, and (ii) different degrees of forward-lookingness. We show that how to form inflation expectations is less relevant when a central bank implements the optimal commitment policy, while it is critical when the central bank adopts the Taylor rule or a simple rule with price-level targeting. Even for the Japanese economy, the effects of monetary policy on economic dynamics significantly change according to expectation formations under rules other than the optimal commitment policy.

A Promised Value Approach to Optimal Monetary Policy

This paper characterizes optimal commitment policy in the New Keynesian model using a novel recursive formulation of the central bank's infinite horizon optimization problem. In our recursive formulation motivated by Kydland and Prescott (1980), promised inflation and output gap---as opposed to lagged Lagrange multipliers---act as pseudo-state variables. Using three well known variants of the model---one featuring inflation bias, one featuring stabilization bias, and one featuring a lower bound constraint on nominal interest rates---we show that the proposed formulation sheds new light on the nature of the intertemporal trade-off facing the central bank.

Optimal Taxation and Debt Management without Commitment

According to the Lucas-Stokey result, a government can structure its debt maturity to guarantee commitment to optimal fiscal policy by future governments. In this paper, we overturn this conclusion, showing that it does not generally hold in the same model and under the same definition of time-consistency as in Lucas-Stokey. Our argument rests on the existence of an overlooked commitment problem that cannot be remedied with debt maturity: a government in the future will not tax on the downward slopping side of the Laffer curve, even if it is ex-ante optimal to do so. In light of this finding, we propose a new framework to characterize time-consistent policy. We consider a Markov Perfect Competitive Equilibrium, where a government reoptimizes sequentially and may deviate from the optimal commitment policy. We find that, in a deterministic economy, any stationary distribution of debt maturity must be flat, with the government owing the same amount at all future dates.

Inventory rationing and markdown strategy in the presence of lead-time sensitive customers

Appropriate customer segmentation, together with tailor-made strategies which dynamically change prices for customers, helps firms allocate resources more effectively. We incorporate markdown tools into the inventory-rationing model with customers segmented by lead-time sensitivity. We characterize the threshold-type optimal commitment policies and propose an efficient algorithm to compute the thresholds.

Endogenous Information and Central Bank Transparency

This paper studies monetary policy under discretion when the central bank ex ante determines information to be acquired and made public. In a general setting, wherein a monetary instrument signals the central bank's private information, I show that an optimal information policy comprises the full disclosure of acquired information, which eliminates the signaling role of the monetary policy. I find that an information policy combined with a discretionary monetary policy implements an optimal commitment policy. Using a simple monetary model, I characterize the optimal policy that publicizes multiple indices, inducing a correlation in public expectations regarding shocks to the economy.

The Pitfalls of Speed-Limit Interest Rate Rules at the Zero Lower Bound

We show that interest rate rules that feed back on the growth rates of target variables (such as output or asset prices) may induce recessions in the presence of a zero lower bound, through purely self-fullling dynamics. This pathology is illustrated in a small New Keynesian model with interest rates responding to the growth rate of output, and in a version of the Iacoviello (2005) model with interest rates responding to the growth rate of house prices and credit growth. Our results provide a cautionary note, contrasting with previous work which has suggested several desirable properties of speed limit rules, namely that they are devices enabling the policymaker (i) to side-step uncertainty about natural rates (ii) to counter booms and busts in asset prices or (iii) to implement optimal commitment policies.

Optimal Energy Commitments with Storage and Intermittent Supply

We formulate and solve the problem of making advance energy commitments for wind farms in the presence of a storage device with conversion losses, mean-reverting price process, and an autoregressive energy generation process from wind. We derive an optimal commitment policy under the assumption that wind energy is uniformly distributed. Then, the stationary distribution of the storage level corresponding to the optimal policy is obtained, from which the economic value of the storage as the relative increase in the expected revenue due to the existence of storage is obtained.

Optimal Monetary Policy with State-Dependent Pricing

This paper studies optimal monetary policy from the timeless perspective in a general model of state-dependent pricing. Firms are modeled as monopolistic competitors subject to idiosyncratic menu cost shocks. We find that, under certain conditions, a policy of zero inflation is optimal both in the long run and in response to aggregate shocks. Key to this finding is an envelope property: at zero inflation, a marginal increase in the rate of inflation has no effect on firms' profits and hence on their probability of repricing. We offer an analytic solution that does not require local approximation or e¢ ciency of the steady state. Under more general conditions, we show numerically that the optimal commitment policy remains very close to strict inflation targeting.

Optimal Monetary Policy with Overlapping Generations of Policymakers

In this paper I study the effect of imperfect central bank commitment on inflationary outcomes. I present a model in which the monetary authority is a committee that consists of members who serve overlapping, finite terms. Older and younger generations of Monetary Policy Committee (MPC) members decide on policy by engaging in a bargaining process. I show that this setup gives rise to a continuous measure of the degree of monetary authority's commitment. The model suggests that the lower the churning rate or the longer the tenure time, the closer social welfare will be to that under optimal commitment policy.

Optimal Monetary Policy with Overlapping Generations of Policymakers

In this paper I study the effect of imperfect central bank commitment on inflationary outcomes. I present a model in which the monetary authority is a committee that consists of members who serve overlapping, finite terms. Older and younger generations of Monetary Policy Committee (MPC) members decide on policy by engaging in a bargaining process. I show that this setup gives rise to a continuous measure of the degree of monetary authority's commitment. The model suggests that the lower the churning rate or the longer the tenure time, the closer social welfare will be to that under optimal commitment policy.

Optimal sustainable monetary policy

In recent monetary policy literature, optimal commitment policy and its variant from a timeless perspective have been studied with emphasis on welfare gains from policy commitment. These policies, however, involve a time-consistency problem called a stabilization bias in forward-looking models. We analyze Chari and Kehoe's [1990. Sustainable plans. Journal of Political Economy 98, 783–802] sustainable equilibrium and examine optimal sustainable policy, i.e. a policymaker's strategy in the best sustainable equilibrium. This paper shows that such a policy becomes consistent with the optimal commitment policy in sufficiently later periods. It also shows that whether the optimal sustainable policy can attain the Ramsey equilibrium outcome depends on the magnitude of shocks hitting the model economy. Moreover, the paper finds a sustainable policy that attains higher social welfare than discretionary policy does.