Abstract
In this paper we discuss scenario reduction methods for risk-averse stochastic optimization problems. Scenario reduction techniques have received some attention in the literature and are used by practitioners, as such methods allow for an approximation of the random variables in the problem with a moderate number of scenarios, which in turn make the optimization problem easier to solve. The majority of works for scenario reduction are designed for classical risk-neutral stochastic optimization problems; however, it is intuitive that in the risk-averse case one is more concerned with scenarios that correspond to high cost. By building upon the notion of effective scenarios recently introduced in the literature, we formalize that intuitive idea and propose a scenario reduction technique for stochastic optimization problems where the objective function is a Conditional Value-at-Risk. Numerical results presented with problems from the literature illustrate the performance of the method and indicate the cases where we expect it to perform well.









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Notes
Models with CVaR have also been used in the context of multistage stochastic programs, but we do not review them here as we focus on the two-stage case in this paper.
By “reducing” the number of scenarios we mean finding another distribution \(\hat{P}\) such that the support of \(\hat{P}\) is strictly contained in \(\Xi \) (the support of \(\hat{P}\) consists of those scenarios \(\xi _i\) for which \(\hat{P}_i>0\)).
In the most general case W and q are random as well, but for our purposes we assume that these quantities are deterministic.
An implementation of ZEBRA can be found in https://sites.google.com/site/sergiogarciaquiles/the-p-median-facility-location-problem.
References
Ahmed, S.: Convexity and decomposition of mean-risk stochastic programs. Math. Program. 106(3), 433–446 (2006)
Altenstedt, F.: Aspects on Asset Liability Management Via Stochastic Programming. Chalmers University of Technology, Gothenburg (2003)
Artzner, P., Delbaen, F., Eber, J.M., Heath, D.: Coherent measures of risk. Math. Finance 9, 203–227 (1999)
Birge, J.R., Louveaux, F.: Introduction to Stochastic Programming. Springer, New York (2011)
Cotton, T.G., Ntaimo, L.: Computational study of decomposition algorithms for mean-risk stochastic linear programs. Math. Program. Comput. 7(4), 471–499 (2015)
Czyzyk, J., Mesnier, M.P., Moré, J.J.: The neos server. IEEE J. Comput. Sci. Eng. 5(3), 68–75 (1998)
Dantzig, G.: Linear Programming and Extensions. Princeton University Press, Princeton (1963)
Dantzig, G.B.: Linear programming under uncertainty. Manag. Sci. 1(3–4), 197–206 (1955)
Dolan, E.D.: The neos server 4.0 administrative guide (Technical Memorandum NO. ANL/MCS-TM-250). Mathematics and Computer Science Division, Argonne National Laboratory (2001)
Dupačová, J., Gröwe-Kuska, N., Römisch, W.: Scenario reduction in stochastic programming. Math. Program. 95(3), 493–511 (2003)
Dupačová, J., Consigli, G., Wallace, S.W.: Scenarios for multistage stochastic programs. Ann. Oper. Res. 100, 25–53 (2000)
Dupačová, J., Gröwe-Kuska, N., Römisch, W.: Scenario reduction in stochastic programming: An approach using probability metrics. Math. Program. 95, 493–511 (2003)
Eichhorn, A., Römisch, W.: Stability of multistage stochastic programs incorporating polyhedral risk measures. Optimization 57(2), 295–318 (2008)
Espinoza, D., Moreno, E.: A primal-dual aggregation algorithm for minimizing conditional value-at-risk in linear programs. Comput. Optim. Appl. 59(3), 617–638 (2014)
Fairbrother, J., Turner, A., Wallace, S.: Scenario generation for stochastic programs with tail risk measures (2015). arXiv preprint arXiv:1511.03074
García, S., Labbé, M., Marín, A.: Solving large p-median problems with a radius formulation. INFORMS J. Comput. 23(4), 546–556 (2011)
García-Bertrand, R., Mínguez, R.: Iterative scenario based reduction technique for stochastic optimization using conditional value-at-risk. Optim. Eng. 15(2), 355–380 (2014)
Gropp, W., Moré, J.J.: Optimization environments and the neos server. In: Buhman, Martin D., Iserles, Arieh (eds.) Approximation Theory and Optimization, pp. 167–182. Cambridge University Press, Cambridge (1997)
Guigues, V., Krätschmer, V., Shapiro, A.: Statistical inference and hypotheses testing of risk averse stochastic programs (2016). arXiv preprint arXiv:1603.07384
Heitsch, H., Römisch, W.: Scenario reduction algorithms in stochastic programming. Comput. Optim. Appl. 24, 187–206 (2003)
Heitsch, H., Römisch, W.: Scenario tree modeling for multistage stochastic programs. Math. Program. 118, 371–406 (2009)
Homem-de-Mello, T., Bayraksan, G.: Monte Carlo sampling-based methods for stochastic optimization. Surv. Oper. Res. Manag. Sci. 19, 56–85 (2014)
Hoyland, K., Kaut, M., Wallace, S.W.: A heuristic for moment-matching scenario generation. Comput. Optim. Appl. 24, 169–185 (2003)
Hoyland, K., Wallace, S.W.: Generating scenario trees for multistage decision problems. Manag. Sci. 47(2), 295–307 (2001)
Linderoth, J., Shapiro, A., Wright, S.: The empirical behavior of sampling methods for stochastic programming. Ann. Oper. Res. 142(1), 215–241 (2006)
Louveaux, F., Smeers, Y.: Optimal investments for electricity generation: a stochastic model and a test problem. In: Ermoliev, Y., Wets, R.J.-B. (eds.) Numericaltechniques for Stochastic Optimization Problems, pp. 445–452. Springer, Berlin (1988)
McKay, M.D., Beckman, R.J., Conover, W.J.: A comparison of three methods for selecting values of input variables in the analysis of output from a computer code. Technometrics 21, 239–245 (1979)
Mehrotra, S., Papp, D.: A cutting surface algorithm for semi-infinite convex programming with an application to moment robust optimization. SIAM J. Optim. 24(4), 1670–1697 (2014)
Miller, N., Ruszczynski, A.: Risk-averse two-stage stochastic linear programming: modeling and decomposition. Oper. Res. 59, 125–132 (2011)
Noyan, N.: Risk-averse two-stage stochastic programming with an application to disaster management. Comput. Oper. Res. 39(3), 541–559 (2012)
Pflug, G.C.: Scenario tree generation for multiperiod financial optimization by optimal discretization. Math. Program. Ser. B 89(2), 251–271 (2001)
Pflug, G.C., Pichler, A.: Approximations for probability distributions and stochastic optimization problems. In: Bertocchi, M., Consigli, G., Dempster, M.A.H. (eds.) Stochastic Optimization Methods in Finance and Energy, pp. 343–387. Springer, New York (2011)
Pineda, S., Conejo, A.: Scenario reduction for risk-averse electricity trading. IET Gener. Transm. Distrib. 4(6), 694–705 (2010)
Rachev, S.T.: Probability Metrics and the Stability of Stochastic Models, vol. 269. Wiley, Hoboken (1991)
Rahimian, H., Bayraksan, G., Homem-de Mello, T.: Identifying effective scenarios in distributionally robust stochastic programs with total variation distance. Math. Program. (2018). https://doi.org/10.1007/s10107-017-1224-6
Rockafellar, R.T., Uryasev, S.P.: Optimization of conditional value-at-risk. J. Risk 2, 21–41 (2000)
Rockafellar, R.T., Wets, R.J.: Variational Analysis: Grundlehren der mathematischen wissenschaften. Springer, Berlin (1998)
Römisch, W., Wets, R.-B.: Stability of \(\varepsilon \)-approximate solutions to convex stochastic programs. SIAM J. Optim. 18(3), 961–979 (2007)
Shapiro, A.: Inference of statistical bounds for multistage stochastic programming problems. Math. Meth. Oper. Res. 58, 57–68 (2003)
Shapiro, A., Dentcheva, D., Ruszczyński, A.: Lectures on Stochastic Programming: Modeling and Theory, 2nd edn. SIAM, Philadelphia (2014)
Wallace, S.W., Ziemba, W.T.: Applications of Stochastic Programming, vol. 5. SIAM, Philadelphia (2005)
Acknowledgements
We thank the anonymous referees for their constructive comments which helped improve the presentation of our results. This work has been supported by FONDECYT 1171145, Chile.
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Arpón, S., Homem-de-Mello, T. & Pagnoncelli, B. Scenario reduction for stochastic programs with Conditional Value-at-Risk. Math. Program. 170, 327–356 (2018). https://doi.org/10.1007/s10107-018-1298-9
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DOI: https://doi.org/10.1007/s10107-018-1298-9