Yuki Teranishi

Optimal monetary policy at the zero-interest-rate bound

What should a central bank do when faced with a weak aggregate demand even after reducing the short-term nominal interest rate to zero? To address this question, we solve a central banks intertemporal loss minimization problem, in which the non-negativity constraint on nominal interest rates is explicitly considered. We find that the optimal path is characterized by policy inertia, in the sense that a zero interest rate policy should be continued for a while even after the natural rate of interest returns to a positive level. By making such a commitment, the central bank is able to achieve higher expected inflation, lower long-term nominal interest rates, and a weaker domestic currency in the adverse periods when the natural rate of interest significantly deviates from a steady-state level.

Smoothed Interest Rate Setting by Central Banks and Staggered Loan Contracts

We investigate a new source of economic stickiness: namely, staggered loan interest rate contracts under monopolistic competition. The paper introduces this mechanism into a standard New Keynesian model. Simulations show that a response to a financial shock is greatly amplified by the staggered loan contracts though a response to a productivity, cost-push or monetary policy shock is not much affected. We derive an approximated loss function and analyse optimal monetary policy. Unlike other models, the function includes a quadratic loss of the first-order difference in loan rates. Thus, central banks have an incentive to smooth the policy rate.

Inflation Targeting and Monetary Policy Activism

We estimate monetary policy activism, defined as responsiveness of the policy interest rate to inflation, among five inflation-targeting countries (the UK, Canada, Sweden, Australia and New Zealand) plus the G3 (the US, Japan and Germany) by applying a time- varying parameter with a stochastic-volatility model. We find that activism of inflation-targeting countries tends to have increased before (not after) the adoption of the inflation-targeting policy framework and that these countries have experienced a decline in activism in recent years, albeit to different degrees. We further explore this result in terms of the constraint of an inflation target range by developing a formal theoretical model in a New Keynesian framework.

Financial Stability in Open Economies

Do financial frictions call for policy cooperation? This paper investigates the implications of financial frictions for monetary policy in the open economy. Welfare analysis shows that there are long-run gains which result from cooperation, but, dynamically, financial frictions per se do not require policy cooperation to improve global welfare over business cycles. In addition, inward-looking financial stability, namely eliminating inefficient fluctuations of loan premiums in the home country, is the optimal monetary policy in the open economy, irrespective of the existence of policy coordination.

Financial Frictions and Policy Cooperation: A Case with Monopolistic Banking and Staggered Loan Contracts

Do financial frictions call for policy cooperation? This paper investigates the implications of simple financial frictions, monopolistic banking together with staggered loan contracts, for monetary policy in open economies in the linear quadratic (LQ) framework. Welfare analysis shows that policy cooperation improves social welfare in the presence of such financial frictions. There also exist long-run gains from cooperation in addition to these by jointly stabilizing inefficient fluctuations over the business cycle, that are usually found in models with price rigidities. The Ramsey optimal steady states differ between cooperation and noncooperation. Such gains from cooperation arise irrespective of the existence of international lending or borrowing.

Global Liquidity Trap

How should monetary policy respond to a global liquidity trap, where the two countries may fall into a liquidity trap simultaneously? Using a two-country New Open Economy Macroeconomics model, we first characterise optimal monetary policy, and show that the optimal rate of inflation in one country is affected by whether or not the other country is in a liquidity trap. Next, we examine how well the optimal monetary policy is approximated by relatively simple monetary policy rules. The interest-rate rule targeting the producer price index performs very well in this respect.

Optimal Macroprudential Policy

We introduce financial market friction through search and matching in the loan market into a standard New Keynesian model. We reveal that the second order approximation of social welfare includes the terms related to credit, such as credit market tightness, the volume of credit, and the loan separation rate, in addition to the inflation rate and consumption under financial market friction. Our analytical result justifies why optimal policy should take credit variation into account. We introduce monetary policy and macroprudential policy measures for financial stability into the model. The optimal outcome is achieved through monetary and macroprudential policies by taking into account not only price stability but also financial stability.