General equilibrium and the new neoclassical synthesis

We present a general equilibrium model of the new neoclassical synthesis that has the same level of generality as the Arrow–Debreu model. This involves a stochastic multi-period economy with a monetary sector and sticky commodity prices. We formulate the notion of a sticky price equilibrium where all agents form rational expectations on prices for commodities and assets, interest rates, and rationing. We present a general result showing that monetary policy imposes no restrictions whatsoever on nominal equilibrium price levels and that the set of sticky price equilibria has a dimension equal to the number of terminal date-events. Stickiness of prices implies that this indeterminacy is real.     

Optimal price‐level drift under commitment in the canonical New Keynesian model

Abstract In both the canonical and many extended versions of the New Keynesian model, optimal monetary policy under commitment implies price‐level stationarity as long as expectations are rational. We show that this is no longer the case if the central bank and private agents make decisions before observing current shocks. The optimal amount of price‐level drift in response to unexpected innovations to inflation is quantitatively important. This result has important implications for monetary policy, including the design of the optimal loss function for the central bank if it cannot commit to its future policies.     

Expectations and the theory of macroeconomic policy: Some recent developments

This paper reviews recent developments in the theory of stabilization policies since the rational expectations revolution. The debate about the neutrality proposition is omitted, and attention is directed at the policy evaluation and the time-inconsistency propositions. It is argued that the open-loop rule of the Friedman type is justifiable only with neutrality, since the techniques of policy evaluation can take into account the restrictions implied by rational expectations. The game-theoretic analyzes by Robert Barro and Donald Gordon support the idea of rules rather than discretion in a novel way, but it is shown that a different reputation mechanism can lead to the “ideal” outcome which is not an equilibrium in the Barro-Gordon analysis.     

Price stabilizing, Pareto improving policies

One possible justification for a stabilization policy is that there is volatility in macro variables that individual agents cannot insure against. We study the simplest possible extension of the stochastic two-period, one agent and one commodity OLG model, where we have added one more period, with only one potential activity, namely, trading of contingent commodities. We assume, however, that markets are incomplete. In this case the Monetary equilibrium is not Pareto Optimal and for an open set of economies an allocation where fluctuations in realized savings are removed, Pareto dominates the monetary equilibrium. This allocation may be implemented by means of a monetary/fiscal policy. The policy considered has a simple rationale, namely that it removes some of the uncertainty that agents face by reducing price, i.e interest rate volatility. We consider two fundamental sources of such volatility, namely, respectively an objective and a subjective signal about the distribution of future endowments. The first case is when agents have rational expectations while the second case is studied in the context of agents having rational beliefs, beliefs which are consistent with empirical observations but not (necessarily) correct.     

Testing the rational expectations and structural neutrality hypotheses: Some further results for the U.K.

In this paper we test directly for the restrictions implied by rational expectations and structural neutrality. The tests are direct in the sense that they employ theLucas output equation father than the approximations to it, which replace the lagged output term by lagged monetary shocks, commonly considered in the literature. The direct approach is considered preferable because it avoids these ad hoc approximations and saves significantly on degrees of freedom. The latter permits us to pursue a fully nested testing procedure, which was not possible in earlier work employing postwar U.K. annual data. The main result is that the rational expectations restrictions are not accepted.     

A note on the interactions among monetary policy,the tax structure and equilibrium output

The proposition that the level of real income is independent of the money stock, originally discussed by quantity theorists, is currently being debated in terms of the rational expectations hypothesis. In this paper, we consider the interactions among monetary policy, the tax structure, and the supply side of the economy and show a potentially important qualification to this proposition. Further, we argue that the impact of monetary policy on output may be perverse.     

Exchange rate fluctuations in an economy with noise traders

This paper analyzes the stability of the exchange rate in an economy with noise traders. Noise trading is restricted to agents investing in the domestic stock market. The agents pricing foreign exchange hold rational expectations. Monetary policy is affected by the behavior of investors in the domestic stock market and in turn affects fundamental stock evaluations as well as noise trading. We show that when monetary policy affects only fundamentalists bifurcation appears in the exchange rate. When monetary policy also affects noise trading, fixing the exchange rate or switching to a low money growth rule imply stock bubbles converge to zero.     

The neutrality of systematic monetary policy in models with a disequilibrium price level

A condition is offered which is necessary and sufficient for the neutrality of aggregate output and the real rate of interest with respect to systematic monetary policy in a general class of stochastic macroeconomic models with rational expectations, additive disturbances, lagged information and a disequilibrium price sequence.     

Expectations and the Stability Problem for Optimal Monetary Policies

A fundamentals based monetary policy rule, which would be the optimal monetary policy without commitment when private agents have perfectly rational expectations, is unstable if in fact these agents follow standard adaptive learning rules. This problem can be overcome if private expectations are observed and suitably incorporated into the policy maker's optimal rule. These strong results extend to the case in which there is simultaneous learning by the policy maker and the private agents. Our findings show the importance of conditioning policy appropriately, not just on fundamentals, but also directly on observed household and firm expectations.     

Monetary Policy,Expectations and Commitment*

Commitment in monetary policy leads to equilibria that are superior to those from optimal discretionary policies. A number of interest‐rate reaction functions and instrument rules have been proposed to implement or approximate commitment policy. We assess these rules in terms of whether they lead to a rational expectations equilibrium that is both locally determinate and stable under adaptive learning by private agents. A reaction function that appropriately depends explicitly on private sector expectations performs particularly well on both counts.     

Inflation targeting in a learning economy: An ABM perspective

This paper investigates the performances of an inflation targeting regime in a learning economy framed as an Agent-Based Model (ABM). We keep our ABM as close as possible to the original New Keynesian (NK) model, but we model the individual behaviour of the agents under procedural rationality à la Simon. Accordingly, we assume that their behaviour is guided by simple rules of thumb – or heuristics – while a continuous learning process governs the evolution of those rules. Under these assumptions that also allow the emergence of agents heterogeneity, we analyze the dynamics of the economy without assuming rational expectations, and study the role that a central bank, implementing an inflation targeting regime via a monetary policy rule, can play in the orientation of these dynamics. Consequently, our main goal is to analyse the interplay between the learning mechanisms operating at the individual level and the features and performances of the inflation targeting regime. Our results point to the prime importance of the credibility of central bank's inflation target regarding macroeconomic stabilisation, as well as the beneficial role played by that target as an anchoring device for private inflation expectations. We also establish the potential welfare cost of imperfect public information and contribute to the current debate on optimal monetary policy rules under imperfect common knowledge and uncertainty.     

The influence of learning and price-level targeting on central bank forward guidance

This paper examines how the effectiveness of central bank forward guidance depends on two key channels: the expectations formation process and the monetary policy regime. The results show that rational expectations relative to an adaptive learning rule amplifies the positive benefits a price-level targeting central bank creates for forward guidance. Specifically, forward guidance generates greater amounts of output and inflation under a price-level than inflation targeting monetary policy regime, but rational expectations overstates these positive benefits compared to adaptive learning. The different responses of expectations between rational expectations and adaptive learning to forward guidance are driving this performance gap. Thus, policymakers should consider how expectations are modeled if forward guidance and price-level targeting are implemented in an economy.     

Variance-minimizing monetary policies with lagged price adjustment and rational expectations

This paper considers a macroeconomic model with rational expectations in which prices are incompletely flexible. Markets therefore fall to clear. In such a model monetary policy is not neutral. The variance of real and nominal quantities and interest rates is sensitive to the parameters of the feedback rule that determines the money supply. The monetary policy that achieves the goal of minimizing the steady-state variance of real output is characterized. We also examine monetary policies that are restricted in their generality and derive ‘second-best’ variance-minimizing feedback rules.     

Money non-neutrality in a Rational Belief Equilibrium with financial assets

Summary. In Rational Beliefs Equilibria money is generically non-neutral. Given the expectational perspective proposed by the Theory of Rational Belief Equilibrium, we show that one of the most important factors in the emergence of money non-neutrality is played by Endogenous Uncertainty. This, in contrast to the Rational Expectations results of money neutrality and policy ineffectiveness, leads to a scenario in which monetary policy has an impact on the real economy and price volatility. The heterogeneity of beliefs together with the distribution and intensity of agents' states of optimism/pessimism can amplify the real effect of monetary policy and/or generate endogenous fluctuations in the economy which are not explained by any exogenous shock. We claim that money non-neutrality is mostly an expectations driven phenomenon. Indeed, additional assumptions of asymmetry of information and/or unanticipated monetary policy are not needed to explain the real effect of monetary policy as it is customary in the New Classical Theory. Received: May 30, 2000; revised version: December 28, 2000     

Monetary policy and heterogeneous expectations

This paper studies the implications for monetary policy of heterogeneous expectations in a New Keynesian model. The assumption of rational expectations is replaced with parsimonious forecasting models where agents select between predictors that are underparameterized. In a Misspecification Equilibrium agents only select the best-performing statistical models. We demonstrate that, even when monetary policy rules satisfy the Taylor principle by adjusting nominal interest rates more than one for one with inflation, there may exist equilibria with Intrinsic Heterogeneity. Under certain conditions, there may exist multiple misspecification equilibria. We show that these findings have important implications for business cycle dynamics and for the design of monetary policy.     

Learning stability in economies with heterogeneous agents

An economy exhibits structural heterogeneity when the forecasts of different agents have different effects on the determination of aggregate variables. We study the important case of economies in which agents' behavior depends on forecasts of aggregate variables and show how different forms of heterogeneity in structure, forecasts, and adaptive learning rules affect the conditions for convergence of adaptive learning towards rational expectations equilibrium. Results are applied to an overlapping generations model and a New Keynesian model of monetary policy.     

Discriminating between rational expectation models: Some evidence

A set of tests to discriminate among alternative rational expectations models in macroeconomics is given. The results tend to favor those specifications in which a feedback rule for monetary policy with a one-quarter lag cannot affect output.     

货币政策有效性与货币政策透明制度的兴起

本文着重探讨货币政策透明性与货币政策有效性之间的关系,目的在于说明货币政策透明制度能够兴起的一个关键因素在于货币政策的透明性有利于提高货币政策的有效性。在标准的“时间不一致性”理论里面,货币政策是否透明对货币政策的效应是没有影响的,因为在这类理论里面,经济主体能够使用所有可获得的信息形成与经济系统相一致的、无偏的估计。但问题的关键在于,这种假设的基本前提在实践中并不完全成立。当考虑到经济主体对经济运行结果和经济运行过程的不完全认知时,货币政策透明性对于促进经济主体的学习过程,稳定和引导公众的通胀预期,进而提高货币政策的有效性就起着至关重要的作用。     

Financial market imperfections and monetary policy strategy

In a model with imperfect money, credit and reserve markets, we examine if an inflation-targeting central bank applying the funds rate operating procedure to indirectly control market interest rates also needs a monetary aggregate as policy instrument. We show that if private agents use information extracted from money and financial markets to form inflation expectations and if interest rate pass-through is incomplete, the central bank can use a narrow monetary aggregate and the discount interest rate as independent and complementary policy instruments to reinforce the credibility of its announcements and the role of inflation target as a nominal anchor for inflation expectations. This study shows how a monetary policy strategy combining inflation targeting and monetary targeting can be conceived to guarantee macroeconomic stability and the credibility of monetary policy. Friedman's k-percent money growth rule, which can generate dynamic instability, and two alternative stabilizing feedback monetary targeting rules are examined.     

固定汇率体系下的货币政策:对未来中国货币政策的探讨

Using a macro dynamic model that is specified for the current Chinese economy, we investigate the monetary policy in China under the assumption that the capital market was “open” under WTO frame-work while the exchange rate was fixed. Our purpose here is to find whether it is possible for China in this case to keep the effective monetary policy for stabilizing the domestic economy. For this, we suggest some institutional arrangements (or restrictions). Given these institutional restrictions, we find that not only the monetary policy can still be effective but also the fixed exchange regime will strengthen the macroeconomic stability shared by both the domestic economy and the economy of its trade partners. The dynamic analysis of the model further shows that the under-valued RMB is necessary for the target exchange rate to be sustainable. Finally, due to the import pattern of the current Chinese economy, RMB appreciation will not help to resolve the trade deficit problem in the Western economy with respect to China.