This volume brings forth a set of papers presented at the conference on
"Varia- tional Inequalities and network equilibrium problems", held in
Erice at the "G. Stam- pacchia" School of the "E. Majorana" Centre for
Scientific Culture in the period 19 25 June 1994. The meeting was
conceived to contribute to the exchange between Variational Analysis and
equilibrium problems, especially those related to network design. Most
of the approaches and viewpoints of these fields are present in the
volume, both as concerns the theory and the applications of equilibrium
problems to transportation, computer and electric networks, to market
behavior, and to bi level programming. Being convinced of the great
importance of equilibrium problems as well as of their complexity, the
organizers hope that the merging of points of view coming from differ-
ent fields will stimulate theoretical research and applications. In this
context Variational and Quasi Variational Inequalities have shown them-
selves to be very important models for equilibrium problems. As a
consequence in the last two decades they have received a lot of
attention both as to mathematical inves- tigation and applications. The
proof that the above mentioned equilibrium problems can be expressed, in
terms of Variational or Quasi Variational Inequalities also in the non
standard and non symmetric cases, has been a crucial improvement.