Reflections on Portfolio Insurance, Portfolio Theory, and Market Simulation with Harry Markowitz

  • Bruce I. Jacobs
  • Kenneth N. Levy


In this paper, we describe some of the areas in which we have been fortunate to work with Harry Markowitzfields in which he was either the originator or was a major developmental force. These include portfolio insurance, portfolio theory, and market simulation.With regard to portfolio insurance, in the years leading up to the crash of October 1987, this strategy was very much in vogue, and we warned that it had the potential to destabilize markets. We believed that portfolio insurance was a major cause of the crash, and we wrote a book on the topic. Harry liked the book, and wrote its foreword, which in his subtle and piercing way makes the distinction between portfolio insurance and portfolio theory and their effects on financial markets.With regard to portfolio theory, we knew that Harry was not only a portfolio theorist, but was also putting his theories into practice, managing a portfolio at Daiwa Securities. We discovered that Harrys expected return estimation procedures used some of our ideas, as we employed his in our portfolio optimization. As our relationship with Harry grew, we worked on finding computationally efficient ways to compute optimal portfolios that included short positions. This interest lead to the development of theorems regarding the conditions under which standard efficient algorithms could be applied to the long-short problem.With regard to market simulation, Harry is a leading figure, having created the simulation language SimScript. We were very interested in studying the behavior of financial markets in response to various stimuli, but models that could simulate realistic markets were not available. Thus, we teamed up with Harry to create the Jacobs Levy Markowitz Simulator (JLMSim).


Portfolio Optimization Portfolio Selection Credit Default Swap Market Portfolio Short Position 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. F. Black, and R. Litterman. Global Portfolio Optimization. Financial Analysts Journal, 48(5):28–43, September/October 1992.Google Scholar
  2. M. Bloch, J. Guerard, H.M. Markowitz, G.P. Todd, and G. Xu. A Comparison of Some Aspects of the U.S. and Japanese Equity Markets. Japan and the World Economy, 5(1):3–26, May 1993.Google Scholar
  3. K.J. Cohen, and J.A. Pogue. An Empirical Evaluation of Alternative Portfolio-Selection Models. Journal of Business, 40(2):166–193, April 1967.CrossRefGoogle Scholar
  4. E.J. Elton, M.J. Gruber, and M.W. Padberg. Simple Criteria for Optimal Portfolio Selection. Journal of Finance, 31(5):1341–1357, December 1976.CrossRefGoogle Scholar
  5. E.J. Elton, M.J. Gruber, and M.W. Padberg. Simple Criteria for Optimal Portfolio Selection: Tracing Out the Efficient Frontier. Journal of Finance, 33(1):296–302, March 1978.CrossRefGoogle Scholar
  6. B.I. Jacobs. Capital Ideas and Market Realities: Option Replication, Investor Behavior, and Stock Market Crashes. Blackwell, Malden, MA, 1999.Google Scholar
  7. B.I. Jacobs. Risk Avoidance and Market Fragility. Financial Analysts Journal, 60(1), January/ February 2004.Google Scholar
  8. B.I. Jacobs. Tumbling Tower of Babel: Subprime Securitization and the Credit Crisis. Financial Analysts Journal, 65(1), January/February 2009.Google Scholar
  9. B.I. Jacobs, and K.N. Levy. Disentangling Equity Return Regularities: New Insights and Investment Opportunities. Financial Analysts Journal, 44(3):18–43, 1988a.CrossRefGoogle Scholar
  10. B.I. Jacobs, and K.N. Levy. Calendar Anomalies: Abnormal Returns at Calendar Turning Points. Financial Analysts Journal, 44(6), 1988b.Google Scholar
  11. B.I. Jacobs, and K.N. Levy, Forecasting the Size Effect. Financial Analysts Journal, 45(3), 1989.Google Scholar
  12. B.I. Jacobs, and K.N. Levy. Equity Management: Quantitative Analysis for Stock Selection. McGraw-Hill, New York, NY, 2000.Google Scholar
  13. B.I. Jacobs, and K.N. Levy. Enhanced Active Equity Portfolios are Trim Equitized Long-Short Portfolios. Journal of Portfolio Management, 33(4):19–25, Summer 2007.Google Scholar
  14. B.I. Jacobs, K.N. Levy, and H.M. Markowitz. Financial Market Simulation. Journal of Portfolio Management, 30th Anniversary Issue:142–152, September 2004.Google Scholar
  15. B.I. Jacobs, K.N. Levy, and H.M. Markowitz. Portfolio Optimization with Factors, Scenarios, and Realistic Short Positions. Operations Research, 53(4):586–599, July/August 2005.Google Scholar
  16. B.I. Jacobs, K.N. Levy, and H.M. Markowitz. Trimability and Fast Optimization of Long-Short Portfolios. Financial Analysts Journal, 62(2):36–46, March/April 2006.Google Scholar
  17. B.I. Jacobs, K.N. Levy, and H.M. Markowitz. Simulating Security Markets in Dynamic and Equilibrium Modes. Forthcoming Financial Analysts Journal, 2010.Google Scholar
  18. B.I. Jacobs, K.N. Levy, H.M. Markowitz, and D. Starer. Equivalence and Relative Computational Complexity of the Critical Line and Elton-Gruber-Padberg Algorithms. Technical Report, Jacobs Levy Equity Management, 2007.Google Scholar
  19. B.I. Jacobs, K.N. Levy, and D. Starer. On the Optimality of Long-Short Strategies. Financial Analysts Journal, 54(2):40–51, March/April 1998.Google Scholar
  20. B.I. Jacobs, K.N. Levy, and D. Starer. Long-Short Portfolio Management: An Integrated Approach. Journal of Portfolio Management, 25(2):23–32, Winter 1999.Google Scholar
  21. H. Levy, and H.M. Markowitz. Approximating Expected Utility by a Function of Mean and Variance. American Economic Review, 69(3):308–317, June 1979.Google Scholar
  22. H.M. Markowitz. Portfolio Selection. Journal of Finance, 7(1):77–91, 1952.CrossRefGoogle Scholar
  23. H.M. Markowitz. The Optimization of a Quadratic Function Subject to Linear Constraints. Naval Research Logistics Quarterly, III:111–133, 1956.Google Scholar
  24. H.M. Markowitz. Portfolio Selection: Efficient Diversification of Investments. Basil Blackwell, Cambridge, MA, 1959.Google Scholar
  25. H.M. Markowitz. Mean-Variance Analysis in Portfolio Choice and Capital Markets. Basil Blackwell, Cambridge, MA, 1987.Google Scholar
  26. H.M. Markowitz. Market Efficiency: A Theoretical Distinction and So What? Financial Analysts Journal, 61(5):17–30, September/October 2005.Google Scholar
  27. W.F. Sharpe. A Simplified Model for Portfolio Analysis. Management Science, 9(2):277–293, January 1963.CrossRefGoogle Scholar
  28. J. Tobin. Liquidity Preference as Behavior Towards Risk. The Review of Economic Studies, 25(2):65–86, February 1958.CrossRefGoogle Scholar
  29. J.L. Treynor, and F. Black. How to Use Security Analysis to Improve Portfolio Selection. Journal of Business, 46(1):66–86, January 1973.CrossRefGoogle Scholar

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© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Jacobs Levy Equity ManagementFlorham ParkUSA

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