Math 582DA
Stochastic Programming Duality: Analysis and Applications

Lisa Korf

Winter 2003, Monday/Wednesday/Friday, 11:30-12:20


Stochastic programming is one methodology for modeling and solving optimization problems under uncertainty. Stochastic programs are mathematical programs in which a probability distribution is incorporated to describe the uncertain parameters present in the problem. A typical application is that of a producer who wants to know how many of various products to produce to maximize his expected profit under uncertain customer demand. Recently stochastic programming has been applied to a variety of problems arising in finance.

Stochastic programming models have a special structure due to the inclusion of the probability distributions in their formulation. Studying duality in stochastic programming leads to an understanding of what happens to the problem under various perturbations of this structure. Duality in stochastic programming is a useful tool for problem analysis (e.g. dual variables interpreted as prices of information), as well as solution methodologies. A major issue that arises is that, because a probability distribution is present in the problem, the problem takes on an infinite-dimensional character. Standard finite-dimensional duality techniques do not apply.

We will explore duality in stochastic programming of both the finite-dimensional and infinite-dimensional variety. Various forms of duality will be explored, along with interpretations. Some issues we will consider once a firm foundation is established are relative duality gaps for nonconvex (including integer) stochastic programs dependent on the type of Lagrangian relaxation considered, and interpretation of dual variables in applications, in particular as applied to portfolio optimization and the pricing of financial derivatives.

Prerequisites: Real Analysis (524/525/526), an Optimization course such as 407, 408, or 515. Some knowledge of Probability Theory is helpful but not required.

Related reading:

  1. Rockafellar, R.T., Conjugate Duality and Optimization, CBMS-NSF Regional Conference Series in Applied Mathematics, SIAM, Philadelphia, 1974.
  2. Rockafellar, R.T. and Wets, R., Stochastic convex programming: basic duality, Pacific Journal of Mathematics, Vol. 62, No. 1, 1976, pp. 173-195.
  3. Rockafellar, R.T. and Wets, R., Stochastic convex programming: relatively complete recourse and induced feasibility, SIAM J. Control and Optimization, Vol. 14, No. 3, May 1976, pp. 574-589.
  4. Korf, L., Stochastic Programming Duality: L multipliers for unbounded constraints with an application to mathematical finance, 2002.
  5. King, A., and Korf, L., Martingale pricing measures in incomplete markets via stochastic programming duality in the dual of L, 2002.