Exchange rate dynamics under alternative optimal interest rate rules

We explore the role of interest rate policy in the exchange rate determination process. Specifically, we derive exchange rate equations from interest rate rules that are theoretically optimal under a few alternative settings. The exchange rate equation depends on its underlying interest rule and its performance could vary across evaluation criteria and sample periods. The exchange rate equation implied by the interest rate rule that allows for interest rate and inflation inertia under commitment offers some encouraging results — exchange rate changes “calibrated” from the equation have a positive and significant correlation with actual data, and offer good direction of change prediction. Our exercise also demonstrates the role of the foreign exchange risk premium in determining exchange rates and the difficulty of explaining exchange rate variability using only policy based fundamentals.     

Home bias,exchange rate disconnect,and optimal exchange rate policy

This paper examines how much the central bank should adjust the interest rate in response to real exchange rate fluctuations. The paper first demonstrates, in a two-country Dynamic Stochastic General Equilibrium (DSGE) model, that home bias in consumption is important to replicate the exchange rate volatility and exchange rate disconnect documented in the data. When home bias is high, the shock to Uncovered Interest rate Parity (UIP) can substantially drive up exchange rate volatility while leaving the volatility of real macroeconomic variables, such as GDP, almost untouched. The model predicts that the volatility of the real exchange rate relative to that of GDP increases with the extent of home bias. This relation is supported by the data. A second-order accurate solution method is employed to find the optimal operational monetary policy rule. Our model suggests that the monetary authority should not seek to vigorously stabilize exchange rate fluctuations. In particular, when the central bank does not take a strong stance against the inflation rate, exchange rate stabilization may induce substantial welfare loss. The model does not detect welfare gain from international monetary cooperation, which extends Obstfeld and Rogoff's [Obstfeld, M., Rogoff, K.,2002. Global implications of self-oriented national monetary rules, Quarterly Journal of Economics May, 503–535] findings to a DSGE model.     

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.     

Can central banks’ monetary policy be described by a linear (augmented) Taylor rule or by a nonlinear rule?

The original Taylor rule establishes a simple linear relation between the interest rate, inflation and the output gap. An important extension to this rule is the assumption of a forward-looking behaviour of central banks. Now they are assumed to target expected inflation and output gap instead of current values of these variables. Using a forward-looking monetary policy reaction function, this paper analyses whether central banks’ monetary policy can indeed be described by a linear Taylor rule or, instead, by a nonlinear rule. It also analyses whether that rule can be augmented with a financial conditions index containing information from some asset prices and financial variables. The results indicate that the monetary behaviour of the European Central Bank and Bank of England is best described by a nonlinear rule, but the behaviour of the Federal Reserve of the United States can be well described by a linear Taylor rule. Our evidence also suggests that only the European Central Bank is reacting to financial conditions.     

The ‘laissez faire’ bias of managed floating

The government of a small open economy trying to manage its exchange rate faces a ‘time consistency’ problem. If markets expect implementation of the optimal linear intervention rule, the government will be tempted to ‘defect’: knowing this, markets will expect less activism; and, in the discretionary equilibrium, this is what they get. How far this credibility problem can shift discretionary policy towards a free float is shown in two popular models of floating rates. One way of offsetting the ‘laissez faire’ bias of discretionary policy is to appoint a relatively ‘conservative’ central banker: but, as the time period of policy action and precommitment shrinks towards zero, the required conservative bias is found to go towards infinity. Other institutional features — such as central bank reputation, contracts and intermediate targets — may be crucial for successful exchange rate management.     

Monetary shocks, the exchange rate, and the trade balance

This paper investigates the response of the exchange rate and the trade balance to monetary policy innovations for the US economy during the period 1973:01–1993:12. The empirical findings indicate that contractionary monetary policy shocks lead to transitory appreciations of the real and the nominal exchange rate. Exchange rate appreciations that are caused by a temporary contractionary shock to monetary policy are correlated with a short-lived improvement in the trade balance which is then followed by a deterioration, giving support to the J-curve hypothesis.     

Real exchange rate persistence and monetary policy rules

The objective of this paper is to analyze the effects of alternative monetary rules on real exchange rate persistence. Using a two-country stochastic dynamic general equilibrium with nominal price stickiness and local currency pricing, we will show how the persistence of purchasing power parity deviations can be related to a monetary theory of these deviations. When monetary policy lean against the wind, there is no relationship of proportionality between the time during which prices remain sticky and the persistence of the response of the real exchange rate: in this case high nominal price rigidity is not sufficient, per se, in generating any persistence following a monetary shock. Moreover, we emphasize the role of interest rates smoothing policies and relative price stickiness within countries in understanding the relationship between the real exchange rate and monetary shocks. With reasonable parameters values, a wide range of monetary policy rules can generate real exchange rate autocorrelations around the ones observed in the data.     

Changing Monetary Policy Rules, Learning, and Real Exchange Rate Dynamics

When the exchange rate is priced by uncovered interest parity and central banks set nominal interest rates according to a reaction function such as the Taylor rule, the real exchange rate will be determined by expected inflation and the output gap or the unemployment gap of the home and foreign countries. This paper examines the implications of these Taylor rule fundamentals for real exchange rate determination. Because the true parameters in central bank policy rules are unknown to the public and change over time, the model is presented in the context of a least squares learning environment. This simple learning model captures the volatility and the major swings in the real deutschemark/euro–dollar exchange rate from 1976 to 2007.     

Do central banks respond to exchange rate movements? A structural investigation

We estimate a small-scale, structural general equilibrium model of a small open economy using Bayesian methods. Our main focus is the conduct of monetary policy in Australia, Canada, New Zealand and the UK. We consider generic Taylor-type rules, where the monetary authority reacts in response to output, inflation, and exchange-rate movements. We perform posterior odds tests to investigate the hypothesis whether central banks do target exchange rates. The main result of this paper is that the central banks of Australia and New Zealand do not, whereas the Bank of Canada and the Bank of England do include the nominal exchange rate in its policy rule. This result is robust for various specification of the policy rule. We also find that terms-of-trade movements do not contribute significantly to domestic business cycles.     

How much should inflation targeters care about the exchange rate?

A DSGE model is used to examine whether including the exchange rate in the central bank’s policy rule can improve economic performance. Smoothing the exchange rate helps both financially-robust economies and financially-vulnerable emerging economies in handling risk premium shocks and, given a small weight placed on the exchange rate, the effects on inflation and output volatility are minimal with demand and cost-push shocks. Financially-vulnerable economies are especially likely to benefit from exchange rate smoothing due to perverse movements of the exchange rate they experience when hit by demand shocks and being more prone to risk premium shocks.     

Inventories and optimal monetary policy in a small open economy

We study how inventory investment affects the design of optimal monetary policy in a New Keynesian small open economy model. We find that under producer currency pricing, when the intratemporal elasticity of substitution is smaller than 1, optimal monetary policy in our model with inventories is similar to a standard model without inventories. However, when the intratemporal elasticity of substitution is larger than 1, inventory investment increases the importance of nominal exchange rate stabilization relative to a standard model without inventories. The importance of nominal exchange rate stabilization increases with the intratemporal elasticity of substitution.     

Bundesbank intervention effects through interest rate policy

This paper investigates the effects of the changes in the Bundesbank's discount and Lombard interest rates on the volatility of European Union country exchange rates relative to the German mark during 1987–93. The first year of the sample period contains the last major realignment in the ERM before its ‘breakdown’ in 1993. Using a parsimonious EGARCH model, we find that the conditional volatility of these exchange rates increased in response to interest rate changes, regardless of the rate change direction. This finding is in direct conflict with Bundesbank's public statements that indicate that its interest rate policy was designed to calm its foreign exchange markets.     

Implications of habit formation for optimal monetary policy

We study the implications for optimal monetary policy of introducing habit formation in consumption into a general equilibrium model with sticky prices. Habit formation affects the model's endogenous dynamics through its effects on both aggregate demand and households’ supply of output. We show that the objective of monetary policy consistent with welfare maximization includes output stabilization, as well as inflation and output gap stabilization. We find that the variance of output increases under optimal policy, even though it acquires a higher implicit weight in the welfare function. We also find that a simple interest rate rule nearly achieves the welfare-optimal allocation, regardless of the degree of habit formation. In this rule, the optimal responses to inflation and the lagged interest rate are both declining in the size of the habit, although super-inertial policies remain optimal.     

The impact of monetary policy on the exchange rate: evidence from three small open economies

This paper studies the impact effect of monetary policy shocks on the exchange rate in Australia, Canada, and New Zealand during the 1990s. Shocks are identified by the reaction of three month market interest rates to policy announcements that were not themselves endogenous to economic news on the same day. The main result is that a 100 basis point contractionary shock will appreciate the exchange rate by 2-3 percent on impact. The association of interest rate hikes with depreciations that is sometimes observed during periods of exchange market pressure is mainly attributable to reverse causality.     

Uncovering the Hit List for Small Inflation Targeters: A Bayesian Structural Analysis

We estimate underlying structural macroeconomic policy objectives of three of the earliest explicit inflation targeters within the context of a small open economy dynamic stochastic general equilibrium model. We assume central banks set policy optimally, such that we can reverse engineer policy objectives from observed time series data. Joint tests of the posterior distributions of these policy preference parameters suggest that the central banks are very similar in their overall objective. None of the central banks show a concern for stabilizing the real exchange rate. All three central banks share a concern for minimizing the volatility in the change in the nominal interest rate. We also show that the resulting optimal policy rule responds to exchange rate movements, even in the case where the central banks do not explicitly care about exchange rate stabilization. This result is also corroborated by results from an alternative simple-rule characterization and estimation of central bank behavior. These last two findings point to the pitfalls of making inferences, from the level of ad hoc simple rules, about what central banks may care about.     

Inflation targeting: What inflation rate to target?

In an economy with nominal rigidities in both an intermediate good sector and a finished good sector, and thus with a natural distinction between CPI and PPI inflation rates, a benevolent central bank faces a tradeoff between stabilizing the two measures of inflation, a final output gap and, unique to our model, a real marginal cost gap in the intermediate sector, so that optimal monetary policy is second-best. We discuss how to implement the optimal policy with minimal information requirement and evaluate the robustness of these simple rules when the central bank may not know the exact sources of shocks or nominal rigidities. A main finding is that a simple hybrid rule under which the short-term interest rate responds to CPI inflation and PPI inflation results in a welfare level close to the optimum, whereas policy rules that ignore PPI inflation or PPI sector shocks can result in significant welfare losses.     

Optimal monetary policy with the cost channel

In the standard new Keynesian framework, an optimizing policy maker does not face a trade-off between stabilizing the inflation rate and stabilizing the gap between actual output and output under flexible prices. An ad hoc, exogenous cost-push shock is typically added to the inflation equation to generate a meaningful policy problem. In this paper, we show that a cost-push shock arises endogenously when a cost channel for monetary policy is introduced into the new Keynesian model. A cost channel is present when firms’ marginal cost depends directly on the nominal rate of interest. Besides providing empirical evidence for a cost channel, we explore its implications for optimal monetary policy. We show that its presence alters the optimal policy problem in important ways. For example, both the output gap and inflation are allowed to fluctuate in response to productivity and demand shocks under optimal monetary policy.     

On the relationship between exchange rates and equity returns: A new approach

This paper employs a new approach in order to investigate the underlying relationship between stock markets and exchange rates. Current approaches suggest that the relative equity market performance of two countries is linked to their exchange rate. In contrast, this study proposes an alternative approach where one global variable – global equity market returns – is believed to have an effect on exchange rates, with the relative interest rate level of a currency determining the sign of the relationship. Our empirical findings suggest that exchange rates and global stock market returns are strongly linked. The value of currencies with higher interest rates is positively related with global equity returns, whereas the value of currencies with lower interest rates is negatively related with global equity returns.     

A multinomial logit approach to exchange rate policy classification with an application to growth

We model a country's de jure exchange rate policy as the choice from a multinomial logit response conditioned on the volatility of its bilateral exchange rate, the volatility of its international reserves, and the volatility of its effective exchange rate. The category with the highest predictive probability implied by the logit regressions serves as our de facto exchange rate policy. An empirical investigation into the relationship between the de facto classifications and GDP growth finds that growth is higher under stable currency-value policies. For non-industrialized countries, a more nuanced characterization of exchange rate policy finds that those who exhibit ‘fear of floating’ experience significantly higher growth.     

A comment on: “The solution to the forward-bias puzzle”

Pippenger (2011) recently proposed a solution to the longstanding forward-bias puzzle. He argues that the puzzling estimates obtained using the standard equation for the efficient markets hypothesis are due to omitted variable bias. He identifies the missing variables as the future change in the forward exchange rate and the future interest differential. When these are added to the standard equation, he finds a one-to-one relationship between the future change in the spot rate and the forward premium. However, we argue that his equation can only test covered interest parity and offers no insight into the forward-bias puzzle.