Ramsey Optimal Policy Research Articles

Optimal Monetary Policy with Government-Provided Unemployment Benefits

Abstract This paper considers a standard New Keynesian model with matching frictions and explores the impact of modeling the opportunity cost of employment as government unemployment transfers. The findings reveal that under such circumstances, maintaining full price stability at all times ceases to be optimal. This outcome persists even when production subsidies are introduced to address inefficiencies caused by imperfect competition in product and factor markets, and when wages are fully flexible and the Hosios condition holds. For a realistic calibration of the opportunity cost, the Ramsey-optimal policy necessitates a positive inflation rate with high volatility. The degree of inflation volatility required increases with the magnitude of unemployment transfers. Consequently, committing to an inflation targeting regime proves to be highly costly in this context. Additionally, the study demonstrates that the optimal inflation variability decreases with workers’ bargaining power. This is because higher workers’ bargaining power leads to reduced labor market fluctuations, thereby lowering the need for large inflation adjustments.

Optimal Policy for Macrofinancial Stability

There is a new and now large literature analyzing government policies for financial stability based on models with endogenous borrowing constraints. These normative analyses build upon the concept of constrained efficient allocation where the social planner is constrained by the same borrowing limit that agents face. In this paper, we show that there exists at least one set of tools implementing the constrained efficient allocation that can also be used by a Ramsey planner to replicate an unconstrained allocation, achieving higher welfare. Constrained efficiency may lead to inaccurate characterizations of welfare maximizing policies relative to Ramsey optimal policy. (JEL E32, E44, E61, G01, H21)

Optimal monetary policy in an estimated SIR model

This paper studies the design of Ramsey optimal monetary policy in a Health New Keynesian (HeNK) model with Susceptible, Infected and Recovered (SIR) agents. The nonlinear model is estimated with maximum likelihood techniques on Euro Area data. Our objective is to deconstruct the mechanism by which contagion risk affects the conduct of monetary policy. If monetary policy is the only game in town, we find that optimal policy features significant deviations from price stability to mitigate the effect of the pandemic. The best outcome is obtained when the optimal Ramsey policy is combined with a lockdown strategy of medium intensity. In this case, monetary policy can concentrate on its price stabilization objective.

Super-Inertial Interest Rate Rules are not Solutions of Ramsey Optimal Policy

Cet article démontre que l’équilibre déterminé par l’engagement d’une Banque Centrale à suivre un règle de taux d’intérêt directeur non stationnaire « super-inertielle » (où la somme des paramètres des taux d’intérêt passés dépasse un et ne dépend pas de la persistence des chocs) ne correspond pas à une solution de l’équilibre stable d’une politique monétaire optimale de Ramsey. Elle déstabilise toujours l’inflation du fait des erreurs d’arrondis et des erreurs de mesure des paramètres du mécanisme de transmission de la politique monétaire. En revanche, l’engagement d’une Banque Centrale à suivre une règle de taux d’intérêt directeur stationnaire où la somme des paramètres des taux d’intérêt passé est strictement plus petite que un et dépend de la persistence des chocs correspond à une solution de l’équilibre stable d’une politique monétaire optimale de Ramsey.

RAMSEY OPTIMAL POLICY IN THE NEW-KEYNESIAN MODEL WITH PUBLIC DEBT

In the discrete-time new-Keynesian model with public debt, Ramsey optimal policy eliminates the indeterminacy of simple-rules multiple equilibria between the fiscal theory of the price level versus new-Keynesian versus an unpleasant equilibrium. If public debt volatility is taken into account into the loss function, the interest rate responds to public debt besides inflation and output gap. Else, the Taylor rule is identical to Ramsey optimal policy when there is zero public debt. The optimal fiscal-rule parameter implies the local stability of public-debt dynamics (“passive” fiscal policy).

Policy Maker’s Credibility with Predetermined Instruments for Forward-Looking Targets

Cette article propose des critères de choix par une banque centrale entre différentes règles de politique monétaire réagissant à l’inflation. Une attention particulière est portée sur la nature non-prédéterminée ou prédéterminée des instruments de politique monétaire. En prenant l’exemple d’une courbe de Phillips des nouveaux Keynésiens, un instrument non-prédéterminé lorsque l’inflation est aussi non-prédéterminée implique un manque extrême de crédibilité et de robustesse de l’ancrage et de la stabilisation des prix, dès lors que la banque centrale ne connaît pas exactement les paramètres de l’économie. En revanche, un instrument prédéterminé est tel qu’une régle proportionnelle ancre l’inflation non-prédéterminée de manière robuste et crédible. Cette règle peut alors être une forme réduite d’une politique optimale à la Ramsey avec un minimum de crédibilité et de robustesse. Nous recommandons de modéliser des politique optimales avec un minimum de crédibilité de la banque centrale plutôt qu’avec des règles proportionnelles en supposant non-prédéterminés à la fois les instruments et les cibles de la politique monétaire.

Optimal fiscal and monetary policy under different fiscal instruments

PurposeThe paper includes characterizing Ramsey policy in a cash-in-advance monetary model, under flexible and sticky prices, and with different fiscal instruments.Design/methodology/approachThe paper analytically and numerically characterizes the dynamic properties of Ramsey allocations. The author computes dynamics by solving second-order approximations to the Ramsey planner’s policy functions around a non-stochastic Ramsey steady state.FindingsThe Friedman rule is not mainly optimal in a cash-in-advance model with distorting taxes. The Ramsey-optimal policy with both taxes on income and consumption calls for a high inflation rate that is extremely volatile, despite the fact that changing prices is costly.Practical implicationsThe optimality of zero nominal interest rate under flexible prices in monetary models is not mainly the case and quite depends on the preferences. The optimality of a zero inflation rate under sticky prices also very much depends on the assumed set of fiscal instruments.Originality/valueThe non-optimality of the Friedman rule under flexible prices is quite new. Moreover, studying the optimal fiscal and monetary policy in a New Keynesian model with a rich set of fiscal instruments is also quite original.

Hopf Bifurcation from New-Keynesian Taylor Rule to Ramsey Optimal Policy

This paper compares different implementations of monetary policy in a new-Keynesian setting. We can show that a shift from Ramsey optimal policy under short-term commitment (based on a negative feedback mechanism) to a Taylor rule (based on a positive feedback mechanism) corresponds to a Hopf bifurcation with opposite policy advice and a change of the dynamic properties. This bifurcation occurs because of the ad hoc assumption that interest rate is a forward-looking variable when policy targets (inflation and output gap) are forward-looking variables in the new-Keynesian theory.

HOPF BIFURCATION FROM NEW-KEYNESIAN TAYLOR RULE TO RAMSEY OPTIMAL POLICY

This paper compares different implementations of monetary policy in a new-Keynesian setting. We can show that a shift from Ramsey optimal policy under short-term commitment (based on a negative feedback mechanism) to a Taylor rule (based on a positive feedback mechanism) corresponds to a Hopf bifurcation with opposite policy advice and a change of the dynamic properties. This bifurcation occurs because of the ad hoc assumption that interest rate is a forward-looking variable when policy targets (inflation and output gap) are forward-looking variables in the new-Keynesian theory.

Policy Maker's Credibility with Predetermined Instruments for Forward-Looking Targets

The aim of the present paper is to provide criteria for a central bank of how to choose among different monetary-policy rules when caring about a number of policy targets such as the output gap and expected inflation. Special attention is given to the question if policy instruments are predetermined or only forward looking. Using the new-Keynesian Phillips curve with a cost-push-shock policy-transmission mechanism, the forward-looking case implies an extreme lack of robustness and of credibility of stabilization policy. The backward-looking case is such that the simple-rule parameters can be the solution of Ramsey optimal policy under limited commitment. As a consequence, we suggest to model explicitly the rational behavior of the policy maker with Ramsey optimal policy, rather than to use simple rules with an ambiguous assumption leading to policy advice that is neither robust nor credible.

The Role of Inflation Target Adjustment in Stabilization Policy

AbstractHow 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.

A Simple Algorithm for Solving Ramsey Optimal Policy with Exogenous Forcing Variables

This article presents an algorithm that extends Ljungqvist and Sargent's (2012) dynamic Stackelberg game to the case of dynamic stochastic general equilibrium models including forcing variables. Its first step is the solution of the discounted augmented linear quadratic regulator as in Hansen and Sargent (2007). It then computes the optimal initial anchor of jump variables such as inflation. We demonstrate that it is of no use to compute non-observable Lagrange multipliers for all periods in order to obtain impulse response functions and welfare. The algorithm presented, however, enables the computation of a history-dependent representation of a Ramsey policy rule that can be implemented by policy makers and estimated within a vector auto-regressive model. The policy instruments depend on the lagged values of the policy instruments and of the private sector's predetermined and jump variables. The algorithm is applied on the new-Keynesian Phillips curve as a monetary policy transmission mechanism.

가계부채 제약하의 통화정책: 2주체 거시모형(TANK)에서의 정량적 분석(Monetary Policy in a Two-Agent Economy with Debt-Constrained Households)

Korean Abstract: 본 연구는 가계 일부가 부채 누적으로 신용시장에서 일정 한도 이상으로는 차입이 어려워 기간간 소비의 평활화(smoothing)에 제약을 받는 상황이 통화정책에 미치는 영향을 금융시장의 불완전성(incomplete financial markets)이 내재된 2주체 소규모 새케인지언 구조모형(Two Agents New Keynesian Model)을 통해 분석하고 있다. 생산비용 상승이라는 경제상황 변화가 있을 때 신용시장에서 차입한도제약을 받는 차입가계와 제약을 받지 않는 저축가계가 소비 및 노동공급에 대해 보이는 비대칭적 반응은 결국 두 가계간 통화정책 전달경로의 확장으로 이어진다. 물가갭과 생산갭을 동시에 고려하여 정책금리를 결정하는 신축적 물가목표 정책의 사회후생 수준은 차입한도제약가계 비중은 물론 모든 경제 상황을 종합적으로 고려하여 정책금리를 결정하는 Ramsey 유형의 최적정책과는 비슷하고 순순하게 물가목표 달성만을 추구하는 엄격한 물가목표 정책의 사회후생 수준보다는 높았다. 이는 가계 일부가 차입한도제약을 받는 상황에서도 신축적 물가목표 정책이 여전히 유효함을 시사한다. 또한 생산비용 상승에 대하여 신축적 물가목표 정책과 최적정책 하에서 소비와 노동공급은 엄격한 물가목표 정책보다는 완만히 조정되는 것으로 나타났다. English Abstract: This paper examines monetary policy quantitatively in a two-agent and small-scale New-Keynesian economy with debt-constrained households who cannot smooth their consumption intertemporally and frictionlessly since highly indebted households are not allowed to borrow above a certain debt ceiling in incomplete financial markets without additional risk premiums due to information asymmetry between savers and borrowers. We find that, in the event of cost shocks, the asymmetric responses of borrowing households without and saving households with dividend incomes lead to different labor supplies and consumptions over heterogeneous households, and eventually to an extension of monetary policy transmission channels. The income effect and low elasticity of labor supply play key roles for such asymmetric responses over heterogeneous households. We also find that the social welfare in flexible inflation targeting (FIT) monetary policy, in which both the inflation gap and output gap are considered in an integrated way for policy-making, is similar to that of Ramsey optimal monetary policy (ROP), in which the shares of debt-constrained households as well as all economic states including both the inflation gap and output gap are considered comprehensively for policy-making, and greater than that of simple inflation targeting (SIT) monetary policy, in which only the inflation gap is considered mechanically for policy-making. Such social welfare implies that FIT policy may still work well even in an economy with a sizable number of debt-constrained households. Further, the responses of cost shocks to consumption and labor supply are dying out more slowly in FIT and ROP policies than in SIT policy.

Ramsey Optimal Policy in the New-Keynesian Model with Public Debt

In the discrete-time new-Keynesian model with public debt, Ramsey optimal policy eliminates the indeterminacy of simple-rules multiple equilibria between the fiscal theory of the price level versus new-Keynesian versus an unpleasant equilibrium. If public debt volatility is taken into account into the loss function, the interest rate responds to public debt besides inflation and output gap. Else, the Taylor rule is identical to Ramsey optimal policy when there is zero public debt. The optimal fiscal-rule parameter implies the local stability of public-debt dynamics (passive fiscal policy).

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 which create a trade-o↵ between inflation and output gap stabilization. We show that this trade-o↵ leads to a non-trivial welfare cost under a standard Taylor rule, even with optimized policy coefficients. We then propose an additional policy tool of an inflation target rule and find that the optimal target needs to be adjusted in a persistent manner and in the opposite direction to the realization of a cost-push shock. The inflation target rule, combined with a Taylor rule, significantly reduces fluctuations in inflation originating from the cost-push shocks and mitigates the policy trade-o↵, resulting in a similar level of welfare to that associated with the Ramsey optimal policy. The welfare implications of the inflation target rule are more pronounced under a flatter Phillips curve.

Ramsey Optimal Policy versus Multiple Equilibria with Fiscal and Monetary Interactions

We consider a frictionless constant endowment economy based on Leeper (1991). In this economy, it is shown that, under an ad-hoc monetary rule and an ad-hoc fiscal rule, there are two equilibria. One has active monetary policy and passive fiscal policy, while the other has passive monetary policy and active fiscal policy. We consider an extended set-up in which the policy maker minimizes a loss function under quasi-commitment, as in Schaumburg and Tambalotti (2007). Under this formulation there exists a unique Ramsey equilibrium, with an interest rate peg and a passive fiscal policy.

THE MACROECONOMIC IMPACT OF MONETARY-FISCAL POLICY IN A “FISCAL DOMINANCE” WORLD

This paper focuses on the question of what monetary and fiscal policy can do and should do in a “fiscal dominance” world. I first highlight that both “amplification” and “fiscal cushion” effects are always at work jointly in determining the evolution of inflation. I find the threshold of maturity of government bonds beyond which more aggressive monetary policy dampens inflation volatility is three quarters. In addition, I conduct welfare analysis to quantitatively evaluate the costs and benefits brought by long-term debt. My results show that the threshold of government debt maturity above which an aggressive monetary policy improves welfare is eight quarters. More importantly, I characterize optimal monetary and fiscal policy using simple and implementable rules. My results indicate an optimal monetary and fiscal combination calls for an aggressive response in both rules. Finally, I find that optimized simple monetary-fiscal rule is significantly welfare inferior to the Ramsey optimal policy.

Macroprudential Capital Regulation in General Equilibrium

We examine macroprudential bank capital policy in a macroeconomic model with a financial accelerator originating in the banking sector. Under Ramsey-optimal policy, the bank capital buffer tracks closely a model-based measure of the credit gap, defined as the gap between equilibrium credit in the economy featuring financial frictions and that in a hypothetical frictionless economy. Simple rules that vary the capital buffer in response to the credit gap perform worse than Ramsey policy, but only modestly so. When monetary policy controls inflation less aggressively, optimal macroprudential responses are smaller. Optimal macroprudential policy operates at a lower frequency than monetary policy.

Super-Inertial Interest Rate Rules Are Not Solutions of Ramsey Optimal Monetary Policy

Giannoni and Woodford (2003) found that the equilibrium determined by commitment to a super-inertial rule (where the sum of the parameters of lags of interest rate exceed ones and does not depend on the auto-correlation of shocks) corresponds to the unique bounded solution of Ramsey optimal policy for the new-Keynesian model. By contrast, this note demonstrates that commitment to an inertial rule (where the sum of the parameters of lags of interest rate is below one and only depends on the auto-correlation of shocks) corresponds to the unique bounded solution.

The Indeterminacy of Determinacy with Fiscal, Macro-Prudential or Taylor Rules

The determinacy of dynamic stochastic general equilibrium models including fiscal, macro-prudential or Taylor rules relies on the assumption that policy instruments are forward-looking when policy targets are also forward-looking. Blanchard and Kahn (1980) determinacy condition does not forbid to assume that policy instruments are backward-looking when policy targets are forward-looking, as it is the case for Ramsey optimal policy under quasi-commitment. There is indeterminacy of determinacy unless six criteria are considered which are in favor of assuming that policy instruments are backward-looking when policy targets are forward-looking.