Model Uncertainity And Liquidity
The paper investigates portfolio strategies and derivative market making when the trader does not know the correct model. One of the puzzles from last summer's LTCM collapse was that when the Russian government defaulted, liquidity dried up. Antidotal evidence suggests that people were unable to trade emerging market debt (as well as corporate bonds) at any price. The drop in the yield of treasury bonds and the rise in the credit spread has been called a "flight to quality." In the paper "small" shocks can leads to a market collapse (lack of liquidity and trade) as the result of uncertainty people have about the "model" of the world. For example, banks that trade derivatives typically assume some model for the stochastic process for an underlying security (e.g., in Black-Scholes this is a log-normality assumption). In the context of the model they price a contract for a customer and hedge their position. In addition to this formal process, banks typically add an ad hoc heuristic to manage the "unforeseen risk." This is the "stress testing" or "value at risk" calculations.In the paper we model uncertainty as Knightian Uncertainty (or more formally the preference of uncertainty aversion). Knightian Uncertainty (and The Choquet integral implied by such preferences) incorporates that risk (the outcome of a coin toss) and uncertainty (the unknown probability that the coin falls heads) enter ones preferences differently. The most well know manifestation of this behavior is the Allais Paradox. Specifically in our paper, we look a the dynamic portfolio problem under Knightian Uncertainty of a derivative market maker. The most striking result (so far) is that while the prices implied by these preferences are quite similar to standard models, the portfolios can be dramatically different. Under Knightian Uncertainty, the position taken in the underlying securities in the "hedge" portfolio can be much larger and even of a different sign. It is this fact that leads us to explore how model uncertainty is closely linked to liquidity. The deeper issues we hope to get at is how the market helps participants "learn" about the right model. In particular, we are exploring how market trade can act to reduce or increase the amount of uncertainty.
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- Grossman, Sanford J & Miller, Merton H, 1988.
" Liquidity and Market Structure,"
Journal of Finance,
American Finance Association, vol. 43(3), pages 617-37, July.
- Epstein, Larry G & Wang, Tan, 1994. "Intertemporal Asset Pricing Under Knightian Uncertainty," Econometrica, Econometric Society, vol. 62(2), pages 283-322, March.
- Lars Peter Hansen & Thomas J. Sargent & Thomas D. Tallarini Jr., 1997.
"Robust Permanent Income and Pricing,"
Levine's Working Paper Archive
596, David K. Levine.
- 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.
- Larry G. Epstein, 2001. "Sharing Ambiguity," American Economic Review, American Economic Association, vol. 91(2), pages 45-50, May.
- Black, Fischer & Scholes, Myron S, 1973. "The Pricing of Options and Corporate Liabilities," Journal of Political Economy, University of Chicago Press, vol. 81(3), pages 637-54, May-June.
- Ho, Thomas & Stoll, Hans R., 1981.
"Optimal dealer pricing under transactions and return uncertainty,"
Journal of Financial Economics,
Elsevier, vol. 9(1), pages 47-73, March.
- Thomas Ho & Hans Stoll, . "Optimal Dealer Pricing Under Transactions and Return Uncertainty," Rodney L. White Center for Financial Research Working Papers 27-79, Wharton School Rodney L. White Center for Financial Research.
- Lawrence H. Summers, 2000. "International Financial Crises: Causes, Prevention, and Cures," American Economic Review, American Economic Association, vol. 90(2), pages 1-16, May.
- Alessandro Prati & Massimo Sbracia, 2002.
"Currency crises and uncertainty about fundamentals,"
Temi di discussione (Economic working papers)
446, Bank of Italy, Economic Research and International Relations Area.
- M. Sbracia & Alessandro Prati, 2002. "Currency Crises and Uncertainty About Fundamentals," IMF Working Papers 02/3, International Monetary Fund.
- Schmeidler, David, 1989.
"Subjective Probability and Expected Utility without Additivity,"
Econometric Society, vol. 57(3), pages 571-87, May.
- David Schmeidler, 1989. "Subjective Probability and Expected Utility without Additivity," Levine's Working Paper Archive 7662, David K. Levine.
- Myron S. Scholes, 2000. "Crisis and Risk Management," American Economic Review, American Economic Association, vol. 90(2), pages 17-21, May.
- Kyle, Albert S, 1985. "Continuous Auctions and Insider Trading," Econometrica, Econometric Society, vol. 53(6), pages 1315-35, November.
- David A. Marshall, 2001. "The crisis of 1998 and the role of the central bank," Economic Perspectives, Federal Reserve Bank of Chicago, issue Q I, pages 2-23.
- Gilboa, Itzhak, 1987. "Expected utility with purely subjective non-additive probabilities," Journal of Mathematical Economics, Elsevier, vol. 16(1), pages 65-88, February.
- Gilboa, Itzhak & Schmeidler, David, 1989. "Maxmin expected utility with non-unique prior," Journal of Mathematical Economics, Elsevier, vol. 18(2), pages 141-153, April.
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