1. Introduction and Motivation 2. Optimality and Complementarity 3. Some Microeconomic Principles 4. Equilibria and Complementarity Problems 5. Variational Inequality Problems 6. Optimization Problems Constrained by Optimization Problems 7. Equilibrium Problems with Equilibrium Constraints 8. Algorithm for LCPs, NCPs, and VIs 9. Some Advanced Algorithms for VI Decomposition, MPCCs and EPECs 10. Natural Gas Market Modeling 11. Electricity and Environmental Markets 12. Multicommodity Equilibrium Models: Accounting for Demand-Side Linkages.