11 Integer Programming: Theory and Algorithms 195
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
11.2 Modeling Logical Conditions . . . . . . . . . . . . . . . . . . 196
11.3 Solving Mixed Integer Linear Programs . . . . . . . . . . . . 199
11.3.1 Linear Programming Relaxation . . . . . . . . . . . . 199
11.3.2 Branch and Bound . . . . . . . . . . . . . . . . . . . . 200
11.3.3 Cutting Planes . . . . . . . . . . . . . . . . . . . . . . 208
11.3.4 Branch and Cut . . . . . . . . . . . . . . . . . . . . . 212
12 IP Models: Constructing an Index Fund 215
12.1 Combinatorial Auctions . . . . . . . . . . . . . . . . . . . . . 215
12.2 The Lockbox Problem . . . . . . . . . . . . . . . . . . . . . . 216
12.3 Constructing an Index Fund . . . . . . . . . . . . . . . . . . . 219
12.3.1 A Large-Scale Deterministic Model . . . . . . . . . . . 220
12.3.2 A Linear Programming Model . . . . . . . . . . . . . 223
12.4 Portfolio Optimization with Minimum Transaction Levels . . 224
12.5 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
12.6 Case Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2266 CONTENTS
13 Dynamic Programming Methods 227
13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
13.1.1 Backward Recursion . . . . . . . . . . . . . . . . . . . 230
13.1.2 Forward Recursion . . . . . . . . . . . . . . . . . . . . 233
13.2 Abstraction of the Dynamic Programming Approach . . . . . 234
13.3 The Knapsack Problem. . . . . . . . . . . . . . . . . . . . . . 237
13.3.1 Dynamic Programming Formulation . . . . . . . . . . 237
13.3.2 An Alternative Formulation . . . . . . . . . . . . . . . 238
13.4 Stochastic Dynamic Programming . . . . . . . . . . . . . . . 239
14 DP Models: Option Pricing 241
14.1 A Model for American Options . . . . . . . . . . . . . . . . . 241
14.2 Binomial Lattice . . . . . . . . . . . . . . . . . . . . . . . . . 243
14.2.1 Specifying the parameters . . . . . . . . . . . . . . . . 244
14.2.2 Option Pricing . . . . . . . . . . . . . . . . . . . . . . 245
15 DP Models: Structuring Asset Backed Securities 249
15.1 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
15.2 Enumerating possible tranches . . . . . . . . . . . . . . . . . 253
15.3 A Dynamic Programming Approach . . . . . . . . . . . . . . 254
15.4 Case Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
16 Stochastic Programming: Theory and Algorithms 257
16.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
16.2 Two Stage Problems with Recourse . . . . . . . . . . . . . . . 258
16.3 Multi Stage Problems . . . . . . . . . . . . . . . . . . . . . . 260
16.4 Decomposition . . . . . . . . . . . . . . . . . . . . . . . . . . 262
16.5 Scenario Generation . . . . . . . . . . . . . . . . . . . . . . . 265
16.5.1 Autoregressive model . . . . . . . . . . . . . . . . . . 265
16.5.2 Constructing scenario trees . . . . . . . . . . . . . . . 267
17 SP Models: Value-at-Risk 273
17.1 Risk Measures . . . . . . . . . . . . . . . . . . . . . . . . . . 273
17.2 Minimizing CVaR . . . . . . . . . . . . . . . . . . . . . . . . 276
17.3 Example: Bond Portfolio Optimization . . . . . . . . . . . . . 278
18 SP Models: Asset/Liability Management 281
18.1 Asset/Liability Management . . . . . . . . . . . . . . . . . . . 281
18.1.1 Corporate Debt Management . . . . . . . . . . . . . . 284
18.2 Synthetic Options . . . . . . . . . . . . . . . . . . . . . . . . 287
18.3 Case Study: Option Pricing with Transaction Costs . . . . . 290
18.3.1 The Standard Problem . . . . . . . . . . . . . . . . . . 291
18.3.2 Transaction Costs . . . . . . . . . . . . . . . . . . . . 292
19 Robust Optimization: Theory and Tools 295
19.1 Introduction to Robust Optimization . . . . . . . . . . . . . . 295
19.2 Uncertainty Sets . . . . . . . . . . . . . . . . . . . . . . . . . 296
19.3 Dierent Flavors of Robustness . . . . . . . . . . . . . . . . . 298CONTENTS 7
19.3.1 Constraint Robustness . . . . . . . . . . . . . . . . . . 298
19.3.2 Objective Robustness . . . . . . . . . . . . . . . . . . 299
19.3.3 Relative Robustness . . . . . . . . . . . . . . . . . . . 301
19.3.4 Adjustable Robust Optimization . . . . . . . . . . . . 303
19.4 Tools and Strategies for Robust Optimization . . . . . . . . . 304
19.4.1 Sampling . . . . . . . . . . . . . . . . . . . . . . . . . 305
19.4.2 Conic Optimization . . . . . . . . . . . . . . . . . . . 305
19.4.3 Saddle-Point Characterizations . . . . . . . . . . . . . 307
20 Robust Optimization Models in Finance 309
20.1 Robust Multi-Period Portfolio Selection . . . . . . . . . . . . 309
20.2 Robust Prot Opportunities in Risky Portfolios . . . . . . . . 313
20.3 Robust Portfolio Selection . . . . . . . . . . . . . . . . . . . . 315
20.4 Relative Robustness in Portfolio Selection . . . . . . . . . . . 317
20.5 Moment Bounds for Option Prices . . . . . . . . . . . . . . . 319
20.6 Additional Exercises . . . . . . . . . . . . . . . . . . . . . . . 320
A Convexity 323
B Cones 325
C A Probability Primer 327
D The Revised Simplex Method 331