Introduction to monetary policy and capital accumulation

The papers in this symposium address the issue of multiple equilibria that can be induced by monetary policy in models with capital accumulation. In particular they examine how the “Taylor Principle”, under which interest rates respond more than proportionately to increases in inflation, can generate multiple equilibria. They also explore the design of policies to avoid the problem of multiple equilibria and indeterminacy.     

Equilibrium Determinacy under Monetary and Fiscal Policies in an Overlapping Generations Model

This paper studies the issue of equilibrium determinacy under monetary and fiscal policy feedback rules in an optimizing general equilibrium model with overlapping generations and flexible prices. It is shown that equilibria may be determinate also when monetary and fiscal policies are both 'passive'. In particular, under passive monetary rules, equilibrium uniqueness is more likely to be verified when fiscal policies are less committed to public debt stabilization.     

Indeterminacy in dynamic models: When Diamond meets Ramsey

We consider an aggregate two-periods overlapping generations model with endogenous labor, consumption in both periods of life, homothetic preferences and productive external effects coming from the average capital and labor. We show that under realistic calibrations of the parameters, in particular a large enough share of first period consumption over the wage income, local indeterminacy of equilibria cannot occur with capital externalities alone. It can nevertheless occur when there are only, even very small, vanishing labor externalities provided that the elasticity of capital-labor substitution and the wage elasticity of the labor supply are large enough. We also show that if labor externalities are slightly stronger, but still small enough to be plausible, and the elasticity of labor supply is larger, local indeterminacy occurs in a Cobb-Douglas economy. Finally, we show that a locally indeterminate steady state is generically characterized by an under-accumulation of capital. It follows therefore that while agents live over a finite number of periods, the conditions for the existence of locally indeterminate equilibria are very similar to those obtained within infinite horizon models and that from this point of view, Diamond meets Ramsey.     

Capital market imperfections in a monetary growth model

Summary. We consider a monetary growth model essentially identical to that of Diamond (1965) and Tirole (1985), except that we explicitly model credit markets, a credit market friction, and an allocative function for financial intermediaries. These changes yield substantially different results than those obtained in more standard models. In particular, if any monetary steady state equilibria exist, there are generally two of them; one of these has a low capital stock and output level, and it is necessarily a saddle. The other steady state has a high capital stock and output level; either it is necessarily a sink, or its stability properties depend on the rate of money creation. It follows that monetary equilibria can be indeterminate, and nonconvergence phenomena can be observed. Increases in the rate of money creation reduce the capital stock in the high-capital-stock steady state. If the high-capital-stock steady state is not a sink for all rates of money growth, then increases in the rate of money growth can induce a Hopf bifurcation. Hence dynamical equilibria can display damped oscillation as a steady state equilibrium is approached, and limit cycles can be observed as well. In addition, in the latter case, high enough rates of inflation induce the kinds of “crises” noted by Bruno and Easterly (1995): when inflation is too high there are no equilibrium paths approaching the high-activity steady state. Received: November 18, 1995; revised version: March 26, 1996     

Expectations and optimal monetary policy: A stability problem revisited

A landmark result in the optimal monetary policy design literature is that fundamental-based interest rate rules invariably lead to rational expectations equilibria (REE) that are not stable under adaptive learning. In this paper, we make a novel information assumption that private agents cannot observe aggregate fundamental shocks, and use simple linear forecasting rules for learning. We find that with fundamental-based rules, there exist limited information equilibria that are stable under learning. Moreover, there are multiple equilibria. Learning can be used as a selection tool to identify a unique equilibrium.     

The macrodynamics of financial fragility within a hard peg arrangement

The paper presents an open-economy macrodynamical growth model with the aim of giving an endogenous characterisation to the process that leads a small country with a currency-board arrangement to accumulate dangerously high levels of external debt and become vulnerable to macroeconomic instability. The macrodynamics of the model results from the combination of the commitment to maintain the peg - that makes liquidity closely dependent on the dynamics of foreign reserves - and the non-linear real and financial interactions that drives the pro-cyclical behaviour of the economy. Within this context, the external financing ease during an economic upswing leads to debt-supported growth and financial fragility; the consequent deterioration of profitability expectations brings about a capital reversal that, in the absence of monetary stabilisation tools, makes the currency arrangement unsustainable. A financial crisis may thus turn into a currency crisis.We run a continuous-time estimation of a non-linear differential equations system for Argentina during the years of the currency-board arrangement. We find that two steady-state solutions exist. The local stability and sensitivity analysis show that both equilibria are unstable and that the qualitative nature of the equilibria depends in particular on lenders' responsiveness to the degree of leverage. We also show that relaxing the assumption on the currency arrangement and allowing for an autonomous monetary policy makes both equilibria stable.     

On the multiplicity of monetary equilibria: Green-Zhou meets Lagos-Wright

Green and Zhou relax the assumption, made in early search-based models of monetary exchange, of indivisible money. Their paper and various extensions make much technical progress, and derive some interesting substantive results. In particular, they show there is an indeterminacy of steady-state monetary equilibria. We reconsider this result in the framework of Lagos and Wright, which is more tractable. We show that a similar multiplicity arises, and is much easier to derive and understand. We also compare the results to those in related nonmonetary models, and discuss how they depend on details, including the number of agents and the timing.     

Optimal Fiscal Policy with Endogenous Time Preference

This paper studies the role of Ramsey taxation under the assumption that the individual rate of time preference is determined by the publicly provided social level of education. We show how intertemporal complementarities of aggregate human capital can generate multiple equilibria and we examine the role of endogenous fiscal policies in equilibrium selection. Our analysis implies a lower optimal government size due to the effect of human capital on time preference.     

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.     

Democratic public good provision

This paper analyzes an overlapping generation model of redistribution and public good provision under repeated voting. Expenditures are financed through age-dependent taxation that distorts human capital investment. Taxes redistribute income both across skill groups and across generations. We focus on politico-economic Markov equilibria and contrast these with the Ramsey allocation under commitment. The model features indeterminate equilibria, with a key role of forward-looking strategic voting. Due to the lack of commitment to future policies, the tax burden may be on the wrong side of the dynamic Laffer curve. Moreover, restrictions on government policies can in some cases be welfare improving.     

A portfolio model of capital flows to emerging markets

Since the crises of the late 1990's, most emerging market economies have built up substantial positive holdings of US dollar treasury bills, while at the same time experiencing a boom in FDI capital inflows. This paper develops a DSGE model of the interaction between an emerging market economy and an advanced economy which incorporates two-way capital flows between the economies. The novel aspect of the paper is to make use of new methods for analyzing portfolio choice in DSGE models. We compare a range of alternative financial market structures, in each case computing equilibrium portfolios. We find that an asymmetric configuration where the emerging economy holds nominal bonds and issues claims on capital (FDI) can achieve a considerable degree of international risk-sharing. This risk-sharing can be enhanced by a more stable monetary policy in the advanced economy.     

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.     

Assessing the effects of financial heterogeneity in a monetary union a DSGE approach

The aim of this article is to analyze how financial heterogeneity can accentuate the cyclical divergences inside a monetary union that faces technological, monetary, budgetary and financial shocks. To this purpose, this study relies on a two-country Dynamic Stochastic General Equilibrium model, where the two countries are supposed to be differently sensitive to the bank capital channel. The model allows us to demonstrate how a given symmetric shock causes cyclical divergences inside a heterogeneous monetary union. On this point, it allows reproducing some stylized facts recently observed in the Euro Area. Moreover, it appears that the more heterogeneous the union, the larger the effects of financial asymmetries on the transmission of shocks. Finally, we show that a common monetary policy contributes to worsen cyclical divergences, in comparison with monetary policies that would be nationally conducted.     

Collateral fluctuations in a monetary economy

This paper studies economy-wide fluctuations that occur endogenously in the presence of monetary and real assets. Using a standard monetary search model, we consider an economy in which agents can increase consumption, over and above what their liquid monetary asset holdings would allow, pledging real assets as collateral for monetary loans. It is shown that, if the liquidation value of real assets is below full market value, a stable cyclical equilibrium can emerge in consumption and capital around the unstable steady state. We also provide conditions for the existence of cycles of higher order, chaos and sunspot equilibria.     

Investment,interest rate rules,and equilibrium determinacy

Summary. By adding endogenous investment to a flexible-price, money-in-the-utility-function model, this paper studies the role that physical capital plays in stabilizing the real side of the economy when the monetary authority follows interest-rate feedback rules. We show that with inelastic labor supply equilibrium uniqueness is ensured under both active and passive monetary policies. For the case where money affects both preferences and technology, the uniqueness result remains true under active monetary policy. With endogenous labor supply, the uniqueness result holds again regardless of the stance of monetary policies for the case with separable leisure, but indeterminacy remains likely under both active and passive monetary policies when leisure is nonseparable.Received: 19 December 2001, Revised: 12 May 2003, JEL Classification Numbers: E52, O42.We are grateful to Jess Benhabib and an anonymous referee for helpful comments and suggestions. Correspondence to: C.K. Yip     

Trend inflation and macroeconomic stability in a small open economy

This paper estimates a small open economy New Keynesian model for Australia with positive trend inflation while allowing for multiple equilibria. We first show the extent to which positive trend inflation can shrink the determinacy region. We then conduct a Bayesian estimation over two separate periods: from 1983Q1 to 1993Q1, covering the pre-inflation-targeting regime, and from 1993Q2 to 2018Q4, covering the inflation-targeting regime. We find that Australian monetary policy before the adoption of inflation-targeting permitted multiple equilibria and self-fulfilling inflation expectations to arise, resulting in exacerbated macroeconomic volatility. The implementation of inflation-targeting in Australia in the early 1990s successfully eradicated equilibrium multiplicity and sunspot shocks, and thereby drove the economy towards greater stability.     

Understanding Markov-switching rational expectations models

We develop a set of necessary and sufficient conditions for equilibria to be determinate in a class of forward-looking Markov-switching rational expectations models and we develop an algorithm to check these conditions in practice. We use three examples, based on the new-Keynesian model of monetary policy, to illustrate our technique. Our work connects applied econometric models of Markov-switching with forward looking rational expectations models and allows an applied researcher to construct the likelihood function for models in this class over a parameter space that includes a determinate region and an indeterminate region.     

Stability, global dynamics and Markov equilibrium in models of endogenous economic growth

This paper studies the local and global dynamics of two-sector models of endogenous growth with economy-wide external effects and taxes on capital and labor. The local analysis classifies the parameter space depending on the number of stationary solutions and local stability of equilibria. The global analysis shows that if taxes are within certain bounds and the size of the external effects on the average level of human capital is smaller than the share of physical capital, the equilibrium path is monotone and therefore a continuous Markov equilibrium can be constructed.