IDEAS home Printed from https://ideas.repec.org/
MyIDEAS: Login to save this article or follow this journal

Robustifying learnability

  • Tetlow, Robert J.
  • von zur Muehlen, Peter

In recent years, the learnability of rational expectations equilibria (REE) and determinacy of economic structures have rightfully joined the usual performance criteria among the sought-after goals of policy design. Some contributions to the literature, including Bullard and Mitra [2002. Learning about monetary policy rules. Journal of Monetary Economics 49 (6), 1105-1139] and Evans and Honkapohja [2006. Monetary Policy, Expectations, and Commitment, Scandinavian Journal of Economics 108, 15-38], have made significant headway in establishing certain features of monetary policy rules that facilitate learning. However a treatment of policy design for learnability in worlds where agents have potentially misspecified their learning models has yet to surface. This paper provides such a treatment. We begin with the notion that because the profession has yet to settle on a consensus model of the economy, it is unreasonable to expect private agents to have collective rational expectations. We assume that agents have only an approximate understanding of the workings of the economy and that their learning the reduced forms of the economy is subject to potentially destabilizing perturbations. The issue is then whether a central bank can design policy to account for perturbations and still assure the learnability of the model. We provide two examples one of which-the canonical New Keynesian business cycle model-serves as a test case. For different parameterizations of a given policy rule, we use structured singular value analysis (from robust control theory) to find the largest ranges of misspecifications that can be tolerated in a learning model without compromising convergence to an REE. In addition, we study the cost, in terms of performance in the steady state of a central bank that acts to robustify learnability on the transition path to REE.

If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.

File URL: http://www.sciencedirect.com/science/article/B6V85-4SY6W26-1/2/45f39d41f560d0db44aaaedcf7be3d8d
Download Restriction: Full text for ScienceDirect subscribers only

As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.

Article provided by Elsevier in its journal Journal of Economic Dynamics and Control.

Volume (Year): 33 (2009)
Issue (Month): 2 (February)
Pages: 296-316

as
in new window

Handle: RePEc:eee:dyncon:v:33:y:2009:i:2:p:296-316
Contact details of provider: Web page: http://www.elsevier.com/locate/jedc

References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:

as in new window
  1. Woodford, M., 1999. "Optimal Monetary Policy Inertia.," Papers 666, Stockholm - International Economic Studies.
  2. Lubik, Thomas A. & Schorfheide, Frank, 2003. "Computing sunspot equilibria in linear rational expectations models," Journal of Economic Dynamics and Control, Elsevier, vol. 28(2), pages 273-285, November.
  3. Giordani, Paolo & Soderlind, Paul, 2004. "Solution of macromodels with Hansen-Sargent robust policies: some extensions," Journal of Economic Dynamics and Control, Elsevier, vol. 28(12), pages 2367-2397, December.
  4. James Bullard & Kaushik Mitra, 2002. "Learning about monetary policy rules," Working Papers 2000-001, Federal Reserve Bank of St. Louis.
  5. Marcet, Albert & Nicolini, Juan Pablo, 1998. "Recurrent Hyperinflations and Learning," CEPR Discussion Papers 1875, C.E.P.R. Discussion Papers.
  6. George W. Evans & Seppo Honkapohja, 2002. "Monetary Policy, Expectations and Commitment," University of Oregon Economics Department Working Papers 2005-11, University of Oregon Economics Department, revised 06 Apr 2005.
  7. George W. Evans & Seppo Honkapohja, 2004. "Adaptive learning and monetary policy design," Macroeconomics 0405008, EconWPA.
  8. Söderström, Ulf, 1999. "Monetary policy with uncertain parameters," SSE/EFI Working Paper Series in Economics and Finance 308, Stockholm School of Economics.
  9. Hansen, Lars Peter & Sargent, Thomas J., 2003. "Robust control of forward-looking models," Journal of Monetary Economics, Elsevier, vol. 50(3), pages 581-604, April.
  10. Kaushik Mitra & Seppo Honkapohja, 2004. "Learning Stability in Economies with Heterogenous Agents," Royal Holloway, University of London: Discussion Papers in Economics 04/17, Department of Economics, Royal Holloway University of London, revised Jul 2004.
  11. Evans, George W. & McGough, Bruce, 2005. "Monetary policy, indeterminacy and learning," Journal of Economic Dynamics and Control, Elsevier, vol. 29(11), pages 1809-1840, November.
  12. Clarida, Richard & Gali, Jordi & Gertler, Mark, 1998. "Monetary policy rules in practice Some international evidence," European Economic Review, Elsevier, vol. 42(6), pages 1033-1067, June.
  13. Honkapohja, S. & Evans, G.W., 2000. "Expectations and the Stability Problem for Optimal Monetary Policies," University of Helsinki, Department of Economics 481, Department of Economics.
  14. James Bullard & Kaushik Mitra, 2003. "Determinacy, learnability, and monetary policy inertia," Working Papers 2000-030, Federal Reserve Bank of St. Louis.
  15. Alexei Onatski & Noah Williams, 2003. "Modeling Model Uncertainty," Journal of the European Economic Association, MIT Press, vol. 1(5), pages 1087-1122, 09.
  16. James Bullard & Stefano Eusepi, 2003. "Did the Great Inflation Occur Despite Policymaker Commitment to a Taylor Rule?," Computing in Economics and Finance 2003 129, Society for Computational Economics.
  17. George W. Evans & Seppo Honkapohja & Noah Williams, 2005. "Generalized Stochastic Gradient Learning," CESifo Working Paper Series 1576, CESifo Group Munich.
  18. Michael Woodford, 2003. "Optimal Interest-Rate Smoothing," Review of Economic Studies, Oxford University Press, vol. 70(4), pages 861-886.
  19. Andrew Levin & Volker Wieland & John C. Williams, 2003. "The Performance of Forecast-Based Monetary Policy Rules Under Model Uncertainty," American Economic Review, American Economic Association, vol. 93(3), pages 622-645, June.
  20. Ben S. Bernanke & Julio J. Rotemberg, 1997. "NBER Macroeconomics Annual 1997, Volume 12," NBER Books, National Bureau of Economic Research, Inc, number bern97-1, October.
  21. McCallum, Bennett T., 1983. "On non-uniqueness in rational expectations models : An attempt at perspective," Journal of Monetary Economics, Elsevier, vol. 11(2), pages 139-168.
  22. Ehrmann, Michael & Smets, Frank, 2001. "Uncertain potential output: implications for monetary policy," Working Paper Series 0059, European Central Bank.
  23. Coenen, Günter, 2003. "Inflation persistence and robust monetary policy design," Working Paper Series 0290, European Central Bank.
  24. Robert J. Tetlow & Peter von zur Muehlen, 1999. "Simplicity versus optimality the choice of monetary policy rules when agents must learn," Finance and Economics Discussion Series 1999-10, Board of Governors of the Federal Reserve System (U.S.).
  25. Nicoletta Batini & Joe Pearlman, 2002. "Too Much Too Soon: Instability and Indeterminacy with Forward-Looking Rules," Computing in Economics and Finance 2002 182, Society for Computational Economics.
  26. Marvin Goodfriend & Robert G. King, 1998. "The new neoclassical synthesis and the role of monetary policy," Working Paper 98-05, Federal Reserve Bank of Richmond.
  27. Walsh, Carl E., 2005. "Parameter misspecification and robust monetary policy rules," Working Paper Series 0477, European Central Bank.
  28. Onatski, Alexei & Stock, James H., 2002. "Robust Monetary Policy Under Model Uncertainty In A Small Model Of The U.S. Economy," Macroeconomic Dynamics, Cambridge University Press, vol. 6(01), pages 85-110, February.
  29. Orphanides, Athanasios & Porter, Richard D. & Reifschneider, David & Tetlow, Robert & Finan, Frederico, 2000. "Errors in the measurement of the output gap and the design of monetary policy," Journal of Economics and Business, Elsevier, vol. 52(1-2), pages 117-141.
  30. Blanchard, Olivier Jean & Kahn, Charles M, 1980. "The Solution of Linear Difference Models under Rational Expectations," Econometrica, Econometric Society, vol. 48(5), pages 1305-11, July.
  31. Robert Tetlow & Peter von zur Muehlen, 2004. "Avoiding Nash Inflation: Bayesian and Robus Responses to Model Uncertainty," Review of Economic Dynamics, Elsevier for the Society for Economic Dynamics, vol. 7(4), pages 869-899, October.
  32. Richard Clarida & Jordi Gali & Mark Gertler, 1999. "The Science of Monetary Policy: A New Keynesian Perspective," NBER Working Papers 7147, National Bureau of Economic Research, Inc.
  33. GEORGE W. EVANS & BRUCE McGOUGH, 2007. "Optimal Constrained Interest-Rate Rules," Journal of Money, Credit and Banking, Blackwell Publishing, vol. 39(6), pages 1335-1356, 09.
  34. Ben S. Bernanke & Michael Woodford, 1997. "Inflation forecasts and monetary policy," Proceedings, Federal Reserve Bank of Cleveland, pages 653-686.
  35. Andrew Levin & Volker Wieland & John C. Williams, 1998. "Robustness of simple monetary policy rules under model uncertainty," Finance and Economics Discussion Series 1998-45, Board of Governors of the Federal Reserve System (U.S.).
  36. Taylor, John B., 1993. "Discretion versus policy rules in practice," Carnegie-Rochester Conference Series on Public Policy, Elsevier, vol. 39(1), pages 195-214, December.
  37. Thomas Lubik & Frank Schorfheide, 2002. "Testing for Indeterminacy:An Application to U.S. Monetary Policy," Economics Working Paper Archive 480, The Johns Hopkins University,Department of Economics, revised Jun 2003.
  38. Giannitsarou, Chryssi, 2005. "E-Stability Does Not Imply Learnability," Macroeconomic Dynamics, Cambridge University Press, vol. 9(02), pages 276-287, April.
  39. Rogoff, Kenneth, 1985. "The Optimal Degree of Commitment to an Intermediate Monetary Target," The Quarterly Journal of Economics, MIT Press, vol. 100(4), pages 1169-89, November.
  40. Robert J. Tetlow & Peter von zur Muehlen, 2000. "Robust monetary policy with misspecified models: does model uncertainty always call for attenuated policy?," Finance and Economics Discussion Series 2000-28, Board of Governors of the Federal Reserve System (U.S.).
  41. Marcet, Albert & Sargent, Thomas J., 1989. "Convergence of least squares learning mechanisms in self-referential linear stochastic models," Journal of Economic Theory, Elsevier, vol. 48(2), pages 337-368, August.
  42. Garratt, Anthony & Hall, Stephen G., 1997. "E-equilibria and adaptive expectations: Output and inflation in the LBS model," Journal of Economic Dynamics and Control, Elsevier, vol. 21(7), pages 1149-1171, June.
  43. Giannoni, Marc P., 2002. "Does Model Uncertainty Justify Caution? Robust Optimal Monetary Policy In A Forward-Looking Model," Macroeconomic Dynamics, Cambridge University Press, vol. 6(01), pages 111-144, February.
  44. Bray, Margaret M & Savin, Nathan E, 1986. "Rational Expectations Equilibria, Learning, and Model Specification," Econometrica, Econometric Society, vol. 54(5), pages 1129-60, September.
  45. Julio Rotemberg & Michael Woodford, 1997. "An Optimization-Based Econometric Framework for the Evaluation of Monetary Policy," NBER Chapters, in: NBER Macroeconomics Annual 1997, Volume 12, pages 297-361 National Bureau of Economic Research, Inc.
Full references (including those not matched with items on IDEAS)

This item is not listed on Wikipedia, on a reading list or among the top items on IDEAS.

When requesting a correction, please mention this item's handle: RePEc:eee:dyncon:v:33:y:2009:i:2:p:296-316. See general information about how to correct material in RePEc.

For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Zhang, Lei)

If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

If references are entirely missing, you can add them using this form.

If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.

If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.

Please note that corrections may take a couple of weeks to filter through the various RePEc services.

This information is provided to you by IDEAS at the Research Division of the Federal Reserve Bank of St. Louis using RePEc data.