Investment and Monetary Policy: Learning and Determinacy of Equilibrium

We explore determinacy and expectational stability (learnability) of rational expectations equilibrium (REE) in New Keynesian (NK) models that include capital. Using a consistent calibration across three different models—labor‐only, firm‐specific capital, or an economy‐wide rental market for capital, we provide a clear picture of when REE is determinate and learnable and when it is not under a variety of monetary policy rules. Our findings make a case for greater optimism concerning the use of such rules in NK models with capital. While Bullard and Mitra’s (2002, 2007) findings for the labor‐only NK model do not always extend to models with capital, we show that determinate and learnable REE can be achieved in NK models with capital if there is (i) plausible capital adjustment costs, (ii) some weight given to output in the policy rule, and/or (iii) a policy of interest rate smoothing.     

Monetary Policy, Determinacy, and Learnability in a Two-Block World Economy

We study how determinacy and learnability of worldwide rational expectations equilibrium may be affected by monetary policy in a simple, two-country, New Keynesian framework under both fixed and flexible exchange rates. We find that open economy considerations may alter conditions for determinacy and learnability relative to closed economy analyses and that new concerns can arise in the analysis of classic topics such as the desirability of exchange rate targeting and monetary policy cooperation.     

The Value of Interest Rate Stabilization Policies When Agents Are Learning

We examine the expectational stability (E-stability) of rational expectations equilibrium in the "New Keynesian" model where monetary policy is optimally derived and interest rate stabilization is added to the central bank's traditional objectives of inflation and output stabilization. We consider both the case where the central bank lacks a commitment technology and the case of full commitment. We show that for both cases, optimal policy rules yield rational expectations equilibria that are E-stable for a wide range of empirically plausible parameter values. These findings stand in contrast to Evans and Honkapohja's findings for optimal monetary policy rules in environments where interest rate stabilization is not a central bank objective.     

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.     

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 Choices in Emerging Market Economies: The Case of High Productivity Growth

We develop a general equilibrium model of an emerging market economy where productivity growth differentials between tradable and non-tradable sectors result in an equilibrium appreciation of the real exchange rate—the so-called Balassa-Samuelson effect. The paper explores the dynamic properties of this economy and the welfare implications of alternative policy rules. We show that the real exchange rate appreciation limits the range of policy rules that, with a given probability, keep inflation and exchange rate within predetermined numerical targets. We also find that the B–S effect raises by an order of magnitude the welfare loss associated with policy rules that prescribe active exchange rate management.     

Interest rate pass-through,monetary policy rules and macroeconomic stability

In this paper we analyze equilibrium determinacy in a sticky price model in which the pass-through from policy rates to retail interest rates is sluggish and potentially incomplete. In addition, we empirically characterize and compare the interest rate pass-through process in the euro area and the U.S. We find that if the pass-through is incomplete in the long run, the standard Taylor principle is insufficient to guarantee equilibrium determinacy. Our empirical analysis indicates that this result might be particularly relevant for bank-based financial systems as for instance that in the euro area.     

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.     

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.     

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.     

Optimal Monetary Policy in a Small Open Economy with Home Bias

We analyze optimal monetary policy in a small open economy characterized by home bias in consumption. Peculiar to our framework is the application of a Ramsey-type analysis to a model of the recent open-economy New Keynesian literature. We show that home bias in consumption is a sufficient condition for inducing the monetary policymaker of an open economy to deviate from a strategy of strict markup stabilization and contemplate some (optimal) degree of exchange rate stabilization. We focus on the optimal setting of policy both in the case of firms setting prices one period in advance and in a gradual fashion subject to adjustment costs. While the first setup allows us to analytically highlight home bias as an independent source of equilibrium markup variability, the second setup allows to study the effects of future expectations on the optimal policy problem and the effect of home bias on optimal inflation volatility. The latter, in particular, is shown to be related to the degree of trade openness in a U-shaped fashion, whereas exchange rate volatility is monotonically decreasing in openness.     

Behind the scenes of abandoning a fixed exchange rate regime

This paper explores the process of abandoning a fixed exchange rate regime during sudden stops in a small open economy. The Bank of Korea’s exchange rate policy reports during the East Asian crisis suggest that its fixed exchange rate regime was forced to collapse due to the depletion of usable foreign reserves, which resulted from the credit policy of the Korean central bank to support domestic banks in need of foreign currency liquidity. To capture the Korean crisis experience, I build a quantitative small open economy model in which, in response to the country risk premium shock, the foreign-currency credit policy of a central bank under fixed regime leads to the exhaustion of international reserves and consequent exchange rate regime shift. This model does well at replicating the observed contraction in Korean aggregate variables.     

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.     

External Constraints on Monetary Policy and the Financial Accelerator

We develop a small open economy macroeconomic model where financial conditions influence aggregate behavior. Our goal is to explore the connection between the exchange rate regime and financial distress. We first show that a calibrated version of the model captures well the behavior of the Korean economy during its financial crisis period of 1997–98. In particular, the model accounts for the sharp increase in lending rates and the large drop in output, employment, investment, and measured productivity. The financial market frictions play an important role, further, explaining roughly half the decline in overall economic activity. We then perform some counterfactual exercises to illustrate how the fixed exchange rate regime likely exacerbated the crisis by tying the hands of monetary policy.     

Rational expectations,changing monetary policy rules,and real exchange rate dynamics

This paper reexamines the explanatory power of Taylor rule fundamentals for real exchange rate determination. We assume the agents know the time-varying parameters in central bank policy rules. The empirical results suggest that a monetary policy rule with regime switching is better able to explain the real Deutschemark/dollar exchange rate from 1976 to 1998 compared with a fixed-regime monetary policy rule. The findings show the importance of accounting for the expectation formation effect in changing policy rules as emphasized by the Lucas critique. Ignoring these effects can undermine the value of the rational expectations models.     

Learning,Monetary Policy,and Asset Prices

We explore the stability properties of interest rate rules granting an explicit response to stock prices in a New Keynesian DSGE model where the presence of non‐Ricardian households makes stock prices nonredundant for the business cycle. We find that responding to stock prices enlarges the policy space for which the equilibrium is both determinate and E‐stable (learnable). In particular, the Taylor principle ceases to be necessary, and determinacy/E‐stability is granted also by mildly passive policy rules. Our results appear to be more prominent in economies featuring a lower elasticity of substitution across differentiated products and/or more rigid labor markets.     

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.     

Learning and the central bank

It is well known that sunspot equilibria may arise under an interest rate operating procedure in which the central bank varies the nominal rate with movements in future inflation (a forward-looking Taylor rule). This paper demonstrates that these sunspot equilibria may be learnable in the sense of E-stability.     

International dimensions of optimal monetary policy

This paper provides a baseline general equilibrium model of optimal monetary policy among interdependent economies with monopolistic firms and nominal rigidities. An inward-looking policy of domestic price stabilization is not optimal when firms’ markups are exposed to currency fluctuations. Such a policy raises exchange rate volatility, leading foreign exporters to charge higher prices vis-à-vis increased uncertainty in the export market. As higher import prices reduce the purchasing power of domestic consumers, optimal monetary rules trade off a larger domestic output gap against lower consumer prices. Optimal rules in a world Nash equilibrium lead to less exchange rate volatility relative to both inward-looking rules and discretionary policies, even when the latter do not suffer from any inflationary (or deflationary) bias. Gains from international monetary cooperation are related in a non-monotonic way to the degree of exchange rate pass-through.