IDEAS home Printed from
MyIDEAS: Login to save this paper or follow this series

Internal Rationality, Imperfect Market Knowledge and Asset Prices

  • Klaus Adam
  • Albert Marcet

We present a decision theoretic framework in which agents are learning about market behavior and that provides microfoundations for models of adaptive learning. Agents are 'internally rational', i.e., maximize discounted expected utility under uncertainty given dynamically consistent subjective beliefs about the future, but agents may not be 'externally rational', i.e., may not know the true stochastic process for payoff relevant variables beyond their control. This includes future market outcomes and fundamentals. We apply this approach to a simple asset pricing model and show that the equilibrium stock price is then determined by investors' expectations of the price and dividend in the next period, rather than by expectations of the discounted sum of dividends. As a result, learning about price behavior affects market outcomes, while learning about the discounted sum of dividends is irrelevant for equilibrium prices. Stock prices equal the discounted sum of dividends only after making very strong assumptions about agents' market knowledge.

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:
Download Restriction: no

Paper provided by Centre for Economic Performance, LSE in its series CEP Discussion Papers with number dp1068.

in new window

Date of creation: Aug 2011
Date of revision:
Handle: RePEc:cep:cepdps:dp1068
Contact details of provider: Web page:

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. Athanasios Orphanides & John Williams, 2004. "Imperfect Knowledge, Inflation Expectations, and Monetary Policy," NBER Chapters, in: The Inflation-Targeting Debate, pages 201-246 National Bureau of Economic Research, Inc.
  2. Klaus Adam, 2003. "Learning and Equilibrium Selection in a Monetary Overlapping Generations Model with Sticky Prices," Review of Economic Studies, Wiley Blackwell, vol. 70(4), pages 887-907, October.
  3. Klaus Adam & Albert Marcet, 2011. "Booms and Busts in Asset Prices," CEP Discussion Papers dp1059, Centre for Economic Performance, LSE.
  4. George W. Evans & Seppo Honkapohja, 2004. "Adaptive learning and monetary policy design," Macroeconomics 0405008, EconWPA.
  5. Lubos Pastor & Pietro Veronesi, 2002. "Stock Valuation and Learning about Profitability," NBER Working Papers 8991, National Bureau of Economic Research, Inc.
  6. Krisztina Molnár & Sergio Santoro, 2010. "Optimal Monetary Policy when Agents are Learning," CESifo Working Paper Series 3072, CESifo Group Munich.
  7. Geweke, John, 2001. "A note on some limitations of CRRA utility," Economics Letters, Elsevier, vol. 71(3), pages 341-345, June.
  8. Michael Woodford, 2005. "Robustly Optimal Monetary Policy with Near Rational Expectations," NBER Working Papers 11896, National Bureau of Economic Research, Inc.
  9. Stefano Eusepi & Bruce Preston, 2008. "Expectations, Learning And Business Cycle Fluctuations," CAMA Working Papers 2008-20, Centre for Applied Macroeconomic Analysis, Crawford School of Public Policy, The Australian National University.
  10. Klaus Adam & Albert Marcet & Juan Pablo Nicolini, 2006. "Learning and Stock Market Volatility," Computing in Economics and Finance 2006 15, Society for Computational Economics.
  11. George W. Evans & Seppo Honkapohja, 2003. "Policy Interaction, Expectations and the Liquidity Trap," University of Oregon Economics Department Working Papers 2003-33, University of Oregon Economics Department, revised 06 Jul 2004.
  12. M. Hashem Pesaran & Davide Pettenuzzo & Allan Timmermann, 2006. "Learning, Structural Instability and Present Value Calculations," CESifo Working Paper Series 1650, CESifo Group Munich.
  13. George W. Evans & Seppo Honkapohja, 2003. "Expectations and the Stability Problem for Optimal Monetary Policies," Review of Economic Studies, Oxford University Press, vol. 70(4), pages 807-824.
  14. Adam, Klaus, 2005. "Learning To Forecast And Cyclical Behavior Of Output And Inflation," Macroeconomic Dynamics, Cambridge University Press, vol. 9(01), pages 1-27, February.
  15. Franklin Allen & Stephen Morris & Hyun Song Shin, 2006. "Beauty Contests and Iterated Expectations in Asset Markets," Review of Financial Studies, Society for Financial Studies, vol. 19(3), pages 719-752.
  16. Thomas J Sargent, 2007. "Evolution and Intelligent Design," Levine's Bibliography 122247000000001821, UCLA Department of Economics.
  17. Lawrence Blume & David Easley, 2006. "If You're so Smart, why Aren't You Rich? Belief Selection in Complete and Incomplete Markets," Econometrica, Econometric Society, vol. 74(4), pages 929-966, 07.
  18. Fudenberg, Drew & Levine, David K, 1993. "Self-Confirming Equilibrium," Econometrica, Econometric Society, vol. 61(3), pages 523-45, May.
  19. Marcet, A. & Nicolini, J.P., 1997. "Recurrent Hyperinflations and Learning," Papers 9721, Centro de Estudios Monetarios Y Financieros-.
  20. Manuel S. Santos & Michael Woodford, 1993. "Rational Asset Pricing Bubbles," Working Papers 9304, Centro de Investigacion Economica, ITAM.
  21. Harrison, J Michael & Kreps, David M, 1978. "Speculative Investor Behavior in a Stock Market with Heterogeneous Expectations," The Quarterly Journal of Economics, MIT Press, vol. 92(2), pages 323-36, May.
  22. George W. Evans & Avik Chakraborty, 2006. "Can Perpetual Learning Explain the Forward Premium Puzzle?," University of Oregon Economics Department Working Papers 2006-8, University of Oregon Economics Department, revised 20 Aug 2006.
  23. Preston, Bruce, 2005. "Learning about Monetary Policy Rules when Long-Horizon Expectations Matter," MPRA Paper 830, University Library of Munich, Germany.
  24. Timmermann, Allan G, 1993. "How Learning in Financial Markets Generates Excess Volatility and Predictability in Stock Prices," The Quarterly Journal of Economics, MIT Press, vol. 108(4), pages 1135-45, November.
  25. Cogley, Timothy & Sargent, Thomas J., 2008. "The market price of risk and the equity premium: A legacy of the Great Depression?," Journal of Monetary Economics, Elsevier, vol. 55(3), pages 454-476, April.
  26. Robert J Aumann, 1999. "Agreeing to Disagree," Levine's Working Paper Archive 512, David K. Levine.
  27. Timmermann, Allan, 1996. "Excess Volatility and Predictability of Stock Prices in Autoregressive Dividend Models with Learning," Review of Economic Studies, Wiley Blackwell, vol. 63(4), pages 523-57, October.
  28. Anderson, Robert M & Sonnenschein, Hugo, 1985. "Rational Expectations Equilibrium with Econometric Models," Review of Economic Studies, Wiley Blackwell, vol. 52(3), pages 359-69, July.
  29. Martin L. Weitzman, 2007. "Subjective Expectations and Asset-Return Puzzles," American Economic Review, American Economic Association, vol. 97(4), pages 1102-1130, September.
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:cep:cepdps:dp1068. 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: ()

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.