AND RELATED ISSUES

In this thesis, we study two kinds of problems related to each other; the multi-leader-follower game and the equilibrium problem with equilibrium constraints, EPEC for short, respective-ly. In the noncooperative game theory, the multi-leader-follower game is a problem where each leader solves a Stackelberg game (single-leader-multi-follower game), which is a spe-cial kind of noncooperative Nash equilibrium problem (NEP). The Stackelberg game can be reformulated as a bilevel optimization problem called the mathematical program with equi-librium constraints (MPEC), in which the lower-level problem contains a complementarity problem (CP) or a variational inequality (VI) problem parameterized by the variable of the upper-level problem. Analogously, the multi-leader-follower game can also be reformulated as the EPEC which is to find equilibria where several players simultaneously solve their own MPECs, each of which is parameterized by decision variables of other players. Studies on the multi-leader-follower game and EPEC have begun only recently. For ex-ample, Sherali considered a true multi-leader-follower game where each leader can exactly anticipate the aggregate followers ’ responses. More recently, Pang and Fukushima introduced a multi-leader-follower games which can be reformulated as the generalized Nash equilibriu