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MONETARY POLICY RULES UNDER UNCERTAINTY: EMPIRICAL EVIDENCE, ADAPTIVE LEARNING, AND ROBUST CONTROL

Published online by Cambridge University Press:  23 November 2005

WENLANG ZHANG
Affiliation:
Center for Empirical Macroeconomics, University of Bielefeld
WILLI SEMMLER
Affiliation:
Center for Empirical Macroeconomics, University of Bielefeld and New School University

Abstract

We first explore empirical evidence of parameter and shock uncertainties in a state-space model with Markov switching. The evidence indicates that uncertainties in the U.S. economy have been too great to accurately define monetary policy rules. We then explore monetary policy rules under uncertainty with two approaches: the RLS learning algorithm and robust control. The former allows the parameters to be learned for a given model. Yet, as our results of the RLS learning in a framework of optimal control indicate, the state variables do not necessarily converge even in a nonstochastic model. The latter, by permitting uncertainty with respect to model misspecification, allows for a broader framework. Our study on robust control shows that robust optimal monetary policy rules reveal a stronger response to fluctuations in inflation and output than when no uncertainty exists, implying that uncertainty does not necessarily require caution.

Type
ARTICLES
Copyright
© 2005 Cambridge University Press

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References

Aguiar A. & M.M.F. Martins 2002 Trend, Cycle, and Nonlinear Trade-off in the Euro-area 1970–2001. Centro De Estudos Macroeconomicos E Previsão, Portugal.
Beck G.W. & V. Wieland 2002 Learning and control in a changing economic environment. Journal of Economic Dynamics and Control 26, 13591377.Google Scholar
Blanchard O. 2005 Monetary policy and unemployment. In W. Semmler (ed.), Monetary Policy and Unemployment—U.S., Euro-Area and Japan, pp. 916. London and New York: Routledge.
Brainard W. 1967 Uncertainty and the effectiveness of policy. American Economic Review 52, 411425.Google Scholar
Brock W.A., S.N. Durlauf, & K.D. West 2003 Policy Evaluation in Uncertain Economic Environment. NBER working paper 10025.
Brock W.A. & A. Xepapadeas 2003 Regulating nonlinear environmental systems under Knightian uncertainty. In R. Arnott, B. Greenwald, R. Kanbur, & B. Nalebuff (eds.), Economics for an Imperfect World: Essays in Honor of Joseph Stiglitz, pp. 127144. Cambridge, MA: MIT Press.
Cagetti M., L.P. Hansen, T. J. Sargent, & N. Williams 2002 Robustness and pricing with uncertain growth. Review of Financial Studies 15, 363404.Google Scholar
Chen Z. & L.G. Epstein 2000 Ambiguity, Risk and Asset Returns in Continuous Time. Working paper, 474, Rochester Center for Economic Research.
Clarida R., J. Gali, & M. Gertler 1998 Monetary policy rules in practice: some international evidence. European Economic Review 42, 10331067.Google Scholar
Clarida R., J. Gali, & M. Gertler 1999 The science of monetary policy: a new Keynesian perspective. Journal of Economic Literature XXXVII, 16611707.Google Scholar
Clarida R., J. Gali, & M. Gertler 2000 Monetary policy rules and macroeconomic stability: evidence and some theory. Quarterly Journal of Economics CXV (1), 147180.Google Scholar
Cogley T. & T.J. Sargent 2001 Evolving post-World War II U.S. inflation dynamics. NBER Macroeconomics Annual 2001.
Cogley T. & T.J. Sargent 2003 Drifts and Volatilities: Monetary Policies and Outcomes in the Post WWII U.S. Working paper 2003–25, Federal Reserve Bank of Atlanta.
Epstein L. and M. Schneider 2001 Recursive Multiple Priors. Working paper 485, Rochester Center for Economic Research.
Escribano A. 2004 Nonlinear error correction: the case of money demand in the United Kingdom (1878–2000). Macroeconomic Dynamics 8, 76116.Google Scholar
Evans G.W. & S. Honkapohja 2001 Learning and Expectations in Macroeconomics. Princeton, NJ: Princeton University Press.
Giannoni M.P. 2002 Does model uncertainty justify caution? Robust optimal monetary policy in a forward-looking model. Macroeconomic Dynamics 6, 111144.Google Scholar
Giordani P. & P. Söderlind 2003 Solution of macromodels with Hansen-Sargent robust policies: summary and some extensions. SSE/EFI Working Paper Series in Economics and Finance 499.
Gonzalez F. & A. Rodriguez 2003 Robust control: a note on the response of the control to changes in the “free” parameter. Manuscript, University of Texas at Austin.
Graham L. & D.J. Snower 2002 The Return of the Long-Run Phillips Curve. Discussion paper 646, Institute for the Study of Labor (IZA).
Greiner A. & W. Semmler 2002 Monetary policy, non-uniqueness of steady states and hysteresis effects. In Reinhard Neck (ed.), Modeling and Control of Economic Systems. Oxford: Elsevier Science.
Grüne L. 1997 An adaptive grid scheme for the discrete Hamilton-Jacobi-Bellman equation. Numerische Mathematik 75, 319337.Google Scholar
Grüne L. & W. Semmler 2004 Using dynamic programming with adaptive grid scheme for optimal control problems in economics. Journal of Economics Dynamics and Control 28, 24272456.Google Scholar
Hansen L.P. & T.J. Sargent 1999 Robustness and commitment: A Monetary Policy Example. Manuscript, Department of Economics, University of Chicago, and Department of Economics, New York University.
Hansen L.P. & T.J. Sargent 2001a Robust Control and Model Uncertainty. Manuscript, Department of Economics, University of Chicago, and Department of Economics, New York University.
Hansen L.P. & T.J. Sargent 2001b Time Inconsistency of Robust Control? Manuscript, Department of Economics, University of Chicago, and Department of Economics, New York University.
Hansen L.P. & T.J. Sargent 2002 Robust Control and Filtering for Macroeconomics. Manuscript, Department of Economics, University of Chicago, and Department of Economics, New York University.
Harvey A.C. 1981 Time Series Models. Oxford: Phillip and Allan.
Isard P., D. Laxton, & A.C. Eliasson 1999 Simple monetary policy rules under model uncertainty. International Tax and Public Finance 6, 537577.Google Scholar
Jenkins P. 2002 Monetary Policy and uncertainty. Bank of Canada Review (Summer), pp. 310.Google Scholar
Karanassou M. & D. Snower 2003 An Antomy of the Phillips Curve. Manuscript, Queen Mary and Birkbeck College, University of London.
Kim C.J. & C.R. Nelson 1999 State-space models with regime switching. Cambridge, MA: MIT Press.
Laxton D., G. Rose, & D. Tambakis 1998 The U.S. Phillips curve: The case for asymmetry. Journal of Economic Dynamics and Control 23, 14591485.Google Scholar
Martin B. & C. Salmon 1999 Should Uncertain Monetary Policy-makers Do Less. Manuscript, Bank of England.
McGough B. 2003 Statistical learning with time-varying parameters. Macroeconomic Dynamics 7, 119139.Google Scholar
Meyer L.H., E.T. Swanson, & V. Wieland 2001 NAIRU Uncertainty and Nonlinear Policy Rules. Finance and Economics Discussion Series, 2001-01, Board of Governors of the Federal Reserve System.
Onatski Alexei & James H. Stock 2002 Robust monetary policy under model uncertainty in a small model of the U.S. economy. Macroeconomic Dynamics 6, 85110.Google Scholar
Orphanides A. & S. van Norden 2002 The unreliability of output gap estimation in real time. Review of Economics and Statistics 84, 569583.Google Scholar
Orphanides A. & J.C. Williams 2002 Imperfect Knowledge, Inflation Expectations and Monetary Policy. FRBSF working paper 2002–04.
Rudebusch G.D. 2001 Is the Fed too timid? Monetary policy in an uncertain world. Review of Economics and Statistics 83, 203217.Google Scholar
Rudebusch G.D. & L.E.O. Svensson 1999 Policy rules for inflation targeting. In John B. Taylor (ed.), Monetary Policy Rules, pp. 203246. Chicago: University of Chicago Press.
Sargent T.J. 1993 Bounded Rationality in Macroeconomics. London: Clarendon Press.
Sargent T.J. 1999 The Conquest of American Inflation. Princeton: Princeton University Press.
Schaling E. 2002 The Nonlinear Phillips Curve and Inflation Forecast Targeting—Symmetric Versus Asymmetric Monetary Policy Rules. Manuscript, http://general.rau.ac.za/economics/Ilse/nonlinphcfin[1].09.09.pdf.
Semmler W., A. Greiner, & W. Zhang 2005 Monetary and Fiscal Policies in the Euro-Area: Macro modeling, learning and empirics. Elsevier Science Publisher, Amsterdam.
Sims C.A. 2001a Pitfalls of a minimax approach to model uncertainty. American Economic Review 91 (2) 5154.Google Scholar
Sims C.A. 2001b Comment on Sargent and Cogley's “Evolving U.S. Postwar Inflation Dynamics.” Manuscript, Princeton University.
Sims C.A. & T. Zha 2002 Macroeconomic Switching. Manuscript, Princeton University, www.princeton.edu/sims.
Söderström Ulf 2002 Monetary policy with uncertain parameters. Scandinavian Journal of Economics 104, 125145.Google Scholar
Svensson L.E.O. 1997 Inflation forecasting targeting: implementing and monitoring inflation targets. European Economic Review 41, 11111146.Google Scholar
Svensson L.E.O. 1999 Inflation targeting: Some extensions. Scandinavian Journal of Economics 101, 337361.Google Scholar
Svensson L.E.O. 2000 Robust Control Made Simple. Manuscript, Princeton University, http://www.princeton.edu/svensson/.
Tambakis D.N. 1998 Monetary Policy with a Convex Phillips Curve and Asymmetric Loss. IMF working paper 98/21.
Tetlow R.J. & P. von zur Muehlen 2001a Simplicity versus optimality: the choice of monetary policy rules when agents must learn. Journal of Economic Dynamics and Control 25, 245279.Google Scholar
Tetlow R.J. & P. von zur Muehlen 2001b Avoiding Nash Inflation: Bayesian and Robust Responses to Model Uncertainty. Manuscript, Board of Governors of the Federal Reserve System.
Tucci M.P. 1997 Adaptive control in the presence of time-vaying parameters. Journal of Economic Dynamics and Control 22, 3947.Google Scholar
Vázquez J. 2003 The Role of the Term-Spread in an Augmented Taylor Rule. Manuscript, Universidad del País Vasco.
Wieland V. 2000 Monetary policy, parameter uncertainty and optimal learning. Journal of Monetary Economics 46, 199228.Google Scholar