Abstract
In the framework of continuous-time market models with specified pricing density, optimal payoffs under increasing law-invariant preferences are known to be anti-monotonic with the pricing density. Consequently, optimal portfolio selection problems can be reformulated as optimization problems on real functions under monotonicity conditions. We solve two basic types of these optimization problems, which makes it possible to obtain in a fairly unified way the optimal payoff for several portfolio selection problems of interest. In particular, we completely solve the optimal portfolio selection problem for an investor with preferences as in cumulative prospect theory or as in Yaari’s dual theory. Extending previous work, we also characterize optimal payoffs when the payoff is required to have a fixed copula with some benchmark (state-dependent constraint). Specifically, we show that if one can determine the optimal payoff under a concave law-invariant objective, then one can also determine the optimal payoff when adding the state-dependent constraint. In the final part of the paper, we consider an extension to (incomplete) market models in which the pricing density is not completely specified. When a sufficient number of payoffs have a known market price, we show that optimal payoffs are anti-monotonic to some pricing density that we explicitly derive from these market prices. As examples, we deal with some exponential Lévy market models and some market models involving Itô processes.
Similar content being viewed by others
Notes
Note that in the mathematical finance literature one often narrows the scope of these market models to so-called complete market models in which the pricing density is unique, and all payoffs are attainable by a self-financing strategy. However, all results on optimal payoffs that are available in the literature for complete market models are also valid in incomplete markets, under the assumption that all participants agree on using a specific pricing density. In this case, however, optimal payoffs are no longer guaranteed to be attainable.
The quantile formulation of the optimal portfolio selection and related optimization problems has a long history. It is intimately connected with the cost minimizing distributional analysis of Dybvig (1988b) and with Hoeffding–Fréchet bounds. For portfolio optimization, it has, for instance, been used in Föllmer and Schied (2004), Carlier and Dana (2006), Burgert and Rüschendorf (2006), Bernard et al. (2014a, b, 2015b), Bernard and Vanduffel (2014), and Kassberger and Liebmann (2012); see also Bernard et al. (2015a) and Bernard et al. (2019) for applications to the ranking of portfolios and explaining their demand. This technique has recently also been put forward and studied in a series of papers, including He and Zhou (2011); Zhang et al. (2011); Jin and Zhou (2008); Xu and Zhou (2013), and Xu (2016); see also the survey paper of Zhou (2011) and the references herein. With respect to risk optimization, it traces its pedigree back to the early eighties (see Rüschendorf 1983).
Xu (2016) develops a Lagrangian relaxation technique that allows derivation of an optimal payoff under rank-dependent utility preferences. It is claimed that this approach also allows to derive the optimal payoff under cumulative prospect theory preferences or under preferences as in Yaari’s dual theory. There is however no proof, and moreover, the stated approach requires inversion of a concave utility, which is at odds with the use of linear utility in Yaari’s dual theory and the use of S-shaped utility functions in cumulative prospect theory.
This is always possible up to a suitable enlargement of the probability space \((\Omega ,\mathcal {A},(\mathcal {A} _{t})_{0\le t\le T},P)\).
We call a functional \(\Psi \) on \(L^{0}(\Omega , P)\) (weakly) increasing if \(\Psi (X+a) \ge \Psi (X)\) for all \(a \ge 0\) and \(X\in L^{0}(\Omega ,P)\).
Recall that two random variables X and Y are called anti-monotonic if \(X(\omega _1) < Y(\omega _2)\) implies \(Y(\omega _2) \le X(\omega _1)\). Anti-monotonicity between two real functions is defined in a similar way.
Note that we do not assume the concavity of w, as is predominantly the case in the CPT literature.
Exponential Lévy market model with Esscher pricing has been introduced in the mathematical finance literature by Gerber and Shiu (1994) and Madan and Milne (1991) and can be considered as one of the classic models; see Eberlein and Keller (1995), Chan (1999), Kallsen and Shiryaev (2002), Esche and Schweizer (2005), Hubalek and Sgarra (2006), Vanduffel et al. (2009), and Benth and Sgarra (2012) for studies of its properties and further motivation.
References
Barlow, R.E., Bartholomew, D.J., Bremner, J.M., Brunk, H.D.: Statistical Inference under Order Restrictions. The Theory and Application of Isotonic Regression. Wiley Series in Probability and Mathematical Statistics. Wiley, Hoboken (1972)
Benth, F.E., Sgarra, C.: The risk premium and the Esscher transform in power markets. Stoch. Anal. Appl. 30(1), 20–43 (2012)
Bernard, C., Vanduffel, S.: Mean-variance optimal portfolios in the presence of a benchmark with applications to fraud detection. Eur. J. Oper. Res. 234(2), 469–480 (2014)
Bernard, C., Boyle, P.P., Vanduffel, S.: Explicit representation of cost-efficient strategies. Finance 35(2), 5–55 (2014a)
Bernard, C., Rüschendorf, L., Vanduffel, S.: Optimal claims with fixed payoff structure. J. Appl. Probab. 51A, 175–188 (2014b)
Bernard, C., Chen, J.S., Vanduffel, S.: Rationalizing investors’ choices. J. Math. Econ. 59, 10–23 (2015a)
Bernard, C., Moraux, F., Rüschendorf, L., Vanduffel, S.: Optimal payoffs under state-dependent constraints. Quant. Financ. 15(7), 1157–1173 (2015b)
Bernard, C., Vanduffel, S., Ye, J.: A new efficiency test for ranking investments: application to hedge fund performance. Econ. Lett. 181, 203–207 (2019)
Björk, T., Murgoci, A., Zhou, X.Y.: Mean-variance portfolio optimization with state-dependent risk aversion. Math. Financ. 24(1), 1–24 (2014)
Bondarenko, O.: Statistical arbitrage and security prices. Rev. Financ. Stud. 16, 875–919 (2003)
Boyle, P., Tian, W.: Portfolio management with constraints. Math. Financ. 17(3), 319–343 (2007)
Breeden, D., Litzenberger, R.: Prices of state-contingent claims implicit in option prices. J. Bus. 51, 621–651 (1978)
Broadie, M., Cvitanić, J., Soner, H.M.: Optimal replication of contingent claims under portfolio constraints. Rev. Financ. Stud. 11(1), 59–79 (1998)
Browne, S.: Beating a moving target: optimal portfolio strategies for outperforming a stochastic benchmark. Financ. Stoch. 3(3), 275–294 (1999)
Burgert, C., Rüschendorf, L.: On the optimal risk allocation problem. Stat. Decis. 24(1), 153–171 (2006)
Carlier, G., Dana, R.-A.: Law invariant concave utility functions and optimization problems with monotonicity and comonotonicity constraints. Stat. Decis. 24(1), 127–152 (2006)
Carr, P., Chou, A.: Breaking barriers. Risk 10, 139–145 (1997)
Chan, T.: Pricing contingent claims on stocks driven by lévy processes. Ann. Appl. Probab. 9, 504–528 (1999)
Cox, J.C., Huang, C.-F.: Optimal consumption and portfolio policies when asset prices follow a diffusion process. J. Econ.Theory 49(1), 33–83 (1989)
Cvitanić, J., Karatzas, I.: Convex duality in constrained portfolio optimization. Ann. Appl. Probab. 2, 767–818 (1992)
Cvitanić, J., Karatzas, I.: Hedging contingent claims with constrained portfolios. Ann. Appl. Probab. 3, 652–681 (1993)
Dong, Y., Sircar, R.: Time-inconsistent portfolio investment problems. In: Crisan, D., Hambly, B., Zariphopoulou, T. (eds.) Stochastic Analysis and Applications, pp. 239–281. Springer, Berlin (2014)
Dybvig, P.H.: Inefficient dynamic portfolio strategies or how to throw away a million dollars in the stock market. Rev. Financ. Stud. 1(1), 67–88 (1988a)
Dybvig, P.H.: Distributional analysis of portfolio choice. J. Bus. 61(3), 369–393 (1988b)
Eberlein, E., Keller, U., et al.: Hyperbolic distributions in finance. Bernoulli 1(3), 281–299 (1995)
Esche, F., Schweizer, M.: Minimal entropy preserves the lévy property: how and why. Stoch. Proces. Appl. 115(2), 299–327 (2005)
Föllmer, H., Leukert, P.: Quantile hedging. Financ. Stoch. 3(3), 251–273 (1999)
Föllmer, H., Leukert, P.: Efficient hedging: cost versus shortfall risk. Financ. Stoch. 4(2), 117–146 (2000)
Föllmer, H., Schied, A.: Stochastic Finance. An Introduction in Discrete Time. de Gruyter, Berlin (2004). 2nd revised and extended edition
Fontana, C., Runggaldier, W.J.: Diffusion-based models for financial markets without martingale measures. In: Risk Measures and Attitudes, pp. 45–81. Springer, Berlin (2013)
Gerber, H.U., Shiu, E.S., et al.: Option pricing by Esscher transforms. Trans. Soc. Actuar. 46(99), 140 (1994)
He, H., Pearson, N.D.: Consumption and portfolio policies with incomplete markets and short-sale constraints: the infinite dimensional case. J. Econ. Theory 54(2), 259–304 (1991)
He, H., Zhou, X.Y.: Portfolio choice via quantiles. Math. Financ. 21, 203–231 (2011)
Hubalek, F., Sgarra, C.: Esscher transforms and the minimal entropy martingale measure for exponential lévy models. Quant. Financ. 6(02), 125–145 (2006)
Jin, H., Zhou, X.: Behavioral portfolio selection in continuous time. Math. Financ. 18, 385–426 (2008)
Kahneman, D., Tversky, A.: Prospect theory: an analysis of decision under risk. Econometrica 47(2), 263–291 (1979)
Kallsen, J., Shiryaev, A.N.: The cumulant process and Esscher’s change of measure. Financ. Stochast 6(4), 397–428 (2002)
Karatzas, I., Lehoczky, J.P., Shreve, S.E.: Optimal portfolio and consumption decisions for a “small investor” on a finite horizon. SIAM J. Control Optim. 25(6), 1557–1586 (1987)
Karatzas, I., Lehoczky, J.P., Shreve, S.E., Xu, G.-L.: Martingale and duality methods for utility maximization in an incomplete market. SIAM J. Control Optim. 29(3), 702–730 (1991)
Karatzas, I., Shreve, S.E., Karatzas, I., Shreve, S.E.: Methods of Mathematical Finance, vol. 39. Springer, Berlin (1998)
Kassberger, S., Liebmann, T.: When are path-dependent payoffs suboptimal? J. Bank. Financ. 36(5), 1304–1310 (2012)
Korn, R.: Stochastic Models for Optimal Investment and Risk Management in Continuous Time. World Scientific, Singapore (1997)
Korn, R., Lindberg, C.: Portfolio optimization for an investor with a benchmark. Decis. Econ. Finan. 37(2), 373–384 (2014)
Kramkov, D., Schachermayer, W.: The asymptotic elasticity of utility functions and optimal investment in incomplete markets. Ann. Appl. Probab. pp. 904–950 (1999)
Lehmann, E.: Testing Statistical Hypotheses. Springer, Berlin (2005)
Lopes, L.L.: Between hope and fear: the psychology of risk. Adv. Exp. Soc. Psychol. 20, 255–295 (1987)
Lopes, L.L., Oden, G.C.: The role of aspiration level in risky choice: a comparison of cumulative prospect theory and SP/A theory. J. Math. Psychol. 43(2), 286–313 (1999)
Madan, D.B., Milne, F.: Option pricing with vg martingale components. Math. Financ. 1(4), 39–55 (1991)
Markowitz, H.: Portfolio selection. J. Financ. 7, 77–91 (1952)
Merton, R.C.: Lifetime portfolio selection under uncertainty: the continuous-time case. Rev. Econ. Stat. 51, 247–257 (1969)
Merton, R.C.: Optimum consumption and portfolio rules in a continuous-time model. J. Econ. Theory 3(4), 373–413 (1971)
Metzger, C., Rüschendorf, L.: Conditional variability ordering of distributions. Ann. Oper. Res. 32(1), 127–140 (1991)
Müller, A., Stoyan, D.: Comparison Methods for Stochastic Models and Risks. Wiley, Chichester (2002)
Platen, E., Heath, D.: A Benchmark Approach to Quantitative Finance. Springer, Berlin (2006)
Pliska, S.R.: A stochastic calculus model of continuous trading: optimal portfolios. Math. Oper. Res. 11(2), 371–382 (1986)
Quiggin, J.: Generalized Expected Utility Theory—The Rank-Dependent Model. Kluwer Academic Publishers, Dordrecht (1993)
Rudloff, B.: Convex hedging in incomplete markets. Appl. Math. Financ. 14(5), 437–452 (2007)
Rudloff, B., Karatzas, I.: Testing composite hypotheses via convex duality. Bernoulli 16, 1224–1239 (2010)
Rüschendorf, L.: Stochastically ordered distributions and monotonicity of the OC of an SPRT. Math. Oper. Forsch. 12, 327–338 (1981)
Rüschendorf, L.: Solution of a statistical optimization problem by rearrangement methods. Metrika 30(1), 55–61 (1983)
Shefrin, H.M., Statman, M.: Behavioral portfolio theory. J. Financ. Quant. Anal. 35(2), 127–151 (2000)
Spivak, G., Cvitanić, J.: Maximizing the probability of a perfect hedge. Ann. Appl. Probab. 9(4), 1303–1328 (1999)
Tversky, A., Kahneman, D.: Advances in prospect theory: cumulative representation of uncertainty. J. Risk Uncertain. 5(4), 297–323 (1992)
Vanduffel, S., Chernih, A., Maj, M., Schoutens, W.: A note on the suboptimality of path-dependent pay-offs in lévy markets. Appl. Math. Financ. 16(4), 315–330 (2009)
von Neumann, J., Morgenstern, O.: Theory of Games and Economic Behavior, 2nd edn. Princeton University Press, Princeton (1947)
Xia, J., Zhou, X.Y.: Arrow-Debreu equilibria for rank-dependent utilities. Math. Financ. 26(3), 558–588 (2012)
Xu, Z.Q.: A new characterization of comonotonicity and its application in behavioral finance. J. Math. Anal. Appl. 418(2), 612–625 (2014)
Xu, Z.Q.: A note on the quantile formulation. Math. Financ. 26(3), 589–601 (2016)
Xu, Z.Q., Zhou, X.Y.: Optimal stopping under probability distortion. Ann. Appl. Probab. 23(1), 251–282 (2013)
Yaari, M.: The dual theory of choice under risk. Econometrica 55, 95–115 (1987)
Zhang, S., Jin, H.Q., Zhou, X.Y.: Behavioral portfolio selection with loss control. Acta Math. Sin. Engl. Ser. 27(2), 255–274 (2011)
Zhou, X.Y.: Mathematicalising behavioural finance. In: Proceedings of the International Congress of Mathematicians (ICM 2010), Hyderabad, India, August 19–27, 2010. Vol. IV: Invited Lectures, pp. 3185–3209. Hackensack, NJ: World Scientific; New Delhi: Hindustan Book Agency (2011)
Acknowledgements
We thank two reviewers for valuable comments and suggestions that helped improving the paper.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Rüschendorf, L., Vanduffel, S. On the construction of optimal payoffs. Decisions Econ Finan 43, 129–153 (2020). https://doi.org/10.1007/s10203-019-00272-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10203-019-00272-9
Keywords
- State-dependent preferences
- Yaari’s dual theory of choice
- Incomplete market models
- Optimization under monotonicity constraints
- Hoeffding–Fréchet bounds