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Portfolio concentration, portfolio inertia, and ambiguous correlation

Author

Listed:
  • Jiang, Julia
  • Liu, Jun
  • Tian, Weidong
  • Zeng, Xudong

Abstract

When an investor is ambiguous about the asset returns' correlation and evaluates the portfolio in a multi-prior framework, we show that the optimal portfolio may contain only a fraction of risky assets. In particular, if the level of ambiguity is high enough, the optimal portfolio contains only the one with the highest Sharpe ratio. Moreover, we demonstrate that the optimal portfolio may be independent of feasible correlation matrices and may not change when the Sharpe ratios of some assets change. Ambiguity-aversion on correlation uncertainty explains portfolio concentration and portfolio inertia in household portfolios and retirement accounts, and the model can explain the growth of indexing and ETFs from an optimal portfolio choice perspective. We further show that these properties do not hold in an alternative smooth ambiguity model, suggesting that the smooth ambiguity model does not depart from the standard model sufficiently to explain portfolio concentration and portfolio inertia.

Suggested Citation

  • Jiang, Julia & Liu, Jun & Tian, Weidong & Zeng, Xudong, 2022. "Portfolio concentration, portfolio inertia, and ambiguous correlation," Journal of Economic Theory, Elsevier, vol. 203(C).
    • Handle: RePEc:eee:jetheo:v:203:y:2022:i:c:s0022053122000539
    DOI: 10.1016/j.jet.2022.105463
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    as
    1. Larry G. Epstein & Shaolin Ji, 2013. "Ambiguous Volatility and Asset Pricing in Continuous Time," The Review of Financial Studies, Society for Financial Studies, vol. 26(7), pages 1740-1786.
    2. Larry G. Epstein & Martin Schneider, 2010. "Ambiguity and Asset Markets," Annual Review of Financial Economics, Annual Reviews, vol. 2(1), pages 315-346, December.
    3. Fabio Maccheroni & Massimo Marinacci & Doriana Ruffino, 2013. "Alpha as Ambiguity: Robust Mean‐Variance Portfolio Analysis," Econometrica, Econometric Society, vol. 81(3), pages 1075-1113, May.
    4. Larry G Epstein & Yoram Halevy, 2019. "Ambiguous Correlation," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 86(2), pages 668-693.
    5. Sujoy Mukerji & Jean-Marc Tallon, 2001. "Ambiguity Aversion and Incompleteness of Financial Markets," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 68(4), pages 883-904.
    6. Larry G. Epstein & Martin Schneider, 2008. "Ambiguity, Information Quality, and Asset Pricing," Journal of Finance, American Finance Association, vol. 63(1), pages 197-228, February.
    7. Judson A. Caskey, 2009. "Information in Equity Markets with Ambiguity-Averse Investors," The Review of Financial Studies, Society for Financial Studies, vol. 22(9), pages 3595-3627, September.
    8. Louis K.C. Chan & Jason Karceski & Josef Lakonishok, 1999. "On Portfolio Optimization: Forecasting Covariances and Choosing the Risk Model," NBER Working Papers 7039, National Bureau of Economic Research, Inc.
    9. repec:taf:jnlbes:v:30:y:2012:i:2:p:212-228 is not listed on IDEAS
    10. Ravi Jagannathan & Tongshu Ma, 2003. "Risk Reduction in Large Portfolios: Why Imposing the Wrong Constraints Helps," Journal of Finance, American Finance Association, vol. 58(4), pages 1651-1683, August.
    11. Milo Bianchi & Jean-Marc Tallon, 2019. "Ambiguity Preferences and Portfolio Choices: Evidence from the Field," PSE-Ecole d'économie de Paris (Postprint) halshs-01886572, HAL.
    12. Ivković, Zoran & Sialm, Clemens & Weisbenner, Scott, 2008. "Portfolio Concentration and the Performance of Individual Investors," Journal of Financial and Quantitative Analysis, Cambridge University Press, vol. 43(3), pages 613-655, September.
    13. H. Henry Cao & Tan Wang & Harold H. Zhang, 2005. "Model Uncertainty, Limited Market Participation, and Asset Prices," The Review of Financial Studies, Society for Financial Studies, vol. 18(4), pages 1219-1251.
    14. Milo Bianchi & Jean-Marc Tallon, 2019. "Ambiguity Preferences and Portfolio Choices: Evidence from the Field," Post-Print halshs-01886572, HAL.
    15. William N. Goetzmann & Alok Kumar, 2008. "Equity Portfolio Diversification," Review of Finance, European Finance Association, vol. 12(3), pages 433-463.
    16. Phelim Boyle & Lorenzo Garlappi & Raman Uppal & Tan Wang, 2012. "Keynes Meets Markowitz: The Trade-Off Between Familiarity and Diversification," Management Science, INFORMS, vol. 58(2), pages 253-272, February.
    17. Christian Gollier, 2011. "Portfolio Choices and Asset Prices: The Comparative Statics of Ambiguity Aversion," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 78(4), pages 1329-1344.
    18. Kan, Raymond & Zhou, Guofu, 2007. "Optimal Portfolio Choice with Parameter Uncertainty," Journal of Financial and Quantitative Analysis, Cambridge University Press, vol. 42(3), pages 621-656, September.
    19. Raman Uppal & Tan Wang, 2003. "Model Misspecification and Underdiversification," Journal of Finance, American Finance Association, vol. 58(6), pages 2465-2486, December.
    20. David Easley & Maureen O'Hara, 2009. "Ambiguity and Nonparticipation: The Role of Regulation," The Review of Financial Studies, Society for Financial Studies, vol. 22(5), pages 1817-1843, May.
    21. Peter Bossaerts & Paolo Ghirardato & Serena Guarnaschelli & William R. Zame, 2010. "Ambiguity in Asset Markets: Theory and Experiment," The Review of Financial Studies, Society for Financial Studies, vol. 23(4), pages 1325-1359, April.
    22. Gabriel Carroll, 2017. "Robustness and Separation in Multidimensional Screening," Econometrica, Econometric Society, vol. 85, pages 453-488, March.
    23. Segal, Uzi & Spivak, Avia, 1990. "First order versus second order risk aversion," Journal of Economic Theory, Elsevier, vol. 51(1), pages 111-125, June.
    24. Mukerji, Sujoy & Tallon, Jean-Marc, 2003. "Ellsberg's two-color experiment, portfolio inertia and ambiguity," Journal of Mathematical Economics, Elsevier, vol. 39(3-4), pages 299-316, June.
    25. Markus K. Brunnermeier & Stefan Nagel, 2008. "Do Wealth Fluctuations Generate Time-Varying Risk Aversion? Micro-evidence on Individuals," American Economic Review, American Economic Association, vol. 98(3), pages 713-736, June.
    26. Marcin Kacperczyk & Clemens Sialm & Lu Zheng, 2005. "On the Industry Concentration of Actively Managed Equity Mutual Funds," Journal of Finance, American Finance Association, vol. 60(4), pages 1983-2011, August.
    27. Gilboa, Itzhak & Schmeidler, David, 1989. "Maxmin expected utility with non-unique prior," Journal of Mathematical Economics, Elsevier, vol. 18(2), pages 141-153, April.
    28. Lorenzo Garlappi & Raman Uppal & Tan Wang, 2007. "Portfolio Selection with Parameter and Model Uncertainty: A Multi-Prior Approach," The Review of Financial Studies, Society for Financial Studies, vol. 20(1), pages 41-81, January.
    29. Huang, Helen Hui & Zhang, Shunming & Zhu, Wei, 2017. "Limited participation under ambiguity of correlation," Journal of Financial Markets, Elsevier, vol. 32(C), pages 97-143.
    30. Philipp K. Illeditsch & Jayant V. Ganguli & Scott Condie, 2021. "Information Inertia," Journal of Finance, American Finance Association, vol. 76(1), pages 443-479, February.
    31. Daniel Ellsberg, 1961. "Risk, Ambiguity, and the Savage Axioms," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 75(4), pages 643-669.
    32. Dimmock, Stephen G. & Kouwenberg, Roy & Mitchell, Olivia S. & Peijnenburg, Kim, 2016. "Ambiguity aversion and household portfolio choice puzzles: Empirical evidence," Journal of Financial Economics, Elsevier, vol. 119(3), pages 559-577.
    33. Peter Klibanoff & Massimo Marinacci & Sujoy Mukerji, 2005. "A Smooth Model of Decision Making under Ambiguity," Econometrica, Econometric Society, vol. 73(6), pages 1849-1892, November.
    34. Harry Markowitz, 1952. "Portfolio Selection," Journal of Finance, American Finance Association, vol. 7(1), pages 77-91, March.
    35. Ang, Andrew & Bekaert, Geert & Liu, Jun, 2005. "Why stocks may disappoint," Journal of Financial Economics, Elsevier, vol. 76(3), pages 471-508, June.
    36. Dow, James & Werlang, Sergio Ribeiro da Costa, 1992. "Uncertainty Aversion, Risk Aversion, and the Optimal Choice of Portfolio," Econometrica, Econometric Society, vol. 60(1), pages 197-204, January.
    37. Easley, David & O'Hara, Maureen, 2010. "Liquidity and valuation in an uncertain world," Journal of Financial Economics, Elsevier, vol. 97(1), pages 1-11, July.
    38. Goldman, M Barry, 1979. "Anti-Diversification or Optimal Programmes for Infrequently Revised Portfolios," Journal of Finance, American Finance Association, vol. 34(2), pages 505-516, May.
    39. Razin, Ronny & Levy, Gilat, 2020. "Combining forecasts in the presence of ambiguity over correlation structures," LSE Research Online Documents on Economics 104641, London School of Economics and Political Science, LSE Library.
    40. Mihm, Maximilian, 2016. "Reference dependent ambiguity," Journal of Economic Theory, Elsevier, vol. 163(C), pages 495-524.
    41. Todd Mitton & Keith Vorkink, 2007. "Equilibrium Underdiversification and the Preference for Skewness," The Review of Financial Studies, Society for Financial Studies, vol. 20(4), pages 1255-1288.
    42. Samuelson, Paul A., 1967. "General Proof that Diversification Pays*," Journal of Financial and Quantitative Analysis, Cambridge University Press, vol. 2(1), pages 1-13, March.
    43. Milo Bianchi & Jean-Marc Tallon, 2019. "Ambiguity Preferences and Portfolio Choices: Evidence from the Field," Management Science, INFORMS, vol. 65(4), pages 1486-1501, April.
    44. Julie Agnew & Pierluigi Balduzzi & Annika Sundén, 2003. "Portfolio Choice and Trading in a Large 401(k) Plan," American Economic Review, American Economic Association, vol. 93(1), pages 193-215, March.
    45. repec:bla:jfinan:v:58:y:2003:i:4:p:1651-1684 is not listed on IDEAS
    46. Chan, Louis K C & Karceski, Jason & Lakonishok, Josef, 1999. "On Portfolio Optimization: Forecasting Covariances and Choosing the Risk Model," The Review of Financial Studies, Society for Financial Studies, vol. 12(5), pages 937-974.
    47. Philipp Karl Illeditsch, 2011. "Ambiguous Information, Portfolio Inertia, and Excess Volatility," Journal of Finance, American Finance Association, vol. 66(6), pages 2213-2247, December.
    48. Valery Polkovnichenko, 2005. "Household Portfolio Diversification: A Case for Rank-Dependent Preferences," The Review of Financial Studies, Society for Financial Studies, vol. 18(4), pages 1467-1502.
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    1. Helen Hui Huang & Yanjie Wang & Shunming Zhang, 2023. "Asset allocation, limited participation and flight‐to‐quality under ambiguity of correlation," International Journal of Finance & Economics, John Wiley & Sons, Ltd., vol. 28(4), pages 4604-4626, October.

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    More about this item

    Keywords

    Correlation ambiguity; Anti-diversification; Correlation-invariant; Portfolio concentration; Portfolio inertia; Smooth ambiguity;
    All these keywords.

    JEL classification:

    • G11 - Financial Economics - - General Financial Markets - - - Portfolio Choice; Investment Decisions
    • G12 - Financial Economics - - General Financial Markets - - - Asset Pricing; Trading Volume; Bond Interest Rates
    • G13 - Financial Economics - - General Financial Markets - - - Contingent Pricing; Futures Pricing
    • D50 - Microeconomics - - General Equilibrium and Disequilibrium - - - General

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