In complementarity theory, which is a relatively new domain of applied mathematics, several kinds of mathematical models and problems related to the study of equilibrium are considered from the point of view of physics as well as economics. In this book the authors have combined complementarity theory, equilibrium of economical systems, and efficiency in Pareto's sense. The authors discuss the use of complementarity theory in the study of equilibrium of economic systems and present results they have obtained. In addition the authors present several new results in complementarity theory and several numerical methods for solving complementarity problems associated with the study of economic equilibrium. The most important notions of Pareto efficiency are also presented. Audience: Researchers and graduate students interested in complementarity theory, in economics, in optimization, and in applied mathematics.

This volume is the result of a conference held at the Institute for Advanced Studies, Vienna. There is still a gap reflected both in fundamental meth odological differences and in the style of analysis between the Walrasian (and Edgeworthian) tradition of general equilibrium theory and the theo retical and policy problems raised in the framework of Keynesian and post-Keynesian macroeconomics. The conference succeeded in bringing together economic theorists working in fields ranging from abstract prob lems of mathematical equilibrium analysis to applied macroeconomic theory, and it is hoped that the present volume will contribute to bridging the above-mentioned hiatus. As organizer of the meeting and editor of its proceedings I want to thank the Institute for Advanced Studies for providing facilities and funds. I am also sincerely grateful to all my colleagues from the Institute for their generous help, in particular to Mrs Monika Herkner without whose assistance and organizational talent the conference would certainly not have been the success it in fact - in the opinion of all participants - turned out to have been. Furthermore, I wish to express my gratitude towards all participants in the meeting and contributors to the volume whose patient support of the whole enterprise proved indispensable. To Mrs Elfriede Auracher I am deeply indebted for her skillful and effective general management of the editorial work and her invaluable assistance in compiling the indexes.

This book deals with the effect of public and semi-public companies on economy. In traditional economic models, several private companies – interested in maximizing their profit – interact (e.g., compete) with each other. Such models help to avoid wild oscillation in production and prices (typical for uncontrolled competition), and to come up with a stable equilibrium solution. The problems become very complex if we take into account the presence of public and semi-public companies – that are interested in public good as well as in the profit. The book contains theoretical results and numerical techniques for computing resulting equilibria. As a case study, it considers the problem of selecting optimal tolls for the public roads – tolls that best balance the public good and the need to recover the cost of building the roads. It is recommended to specialists in economics as well as to students interested in learning the corresponding economic models.

This Volume contains the (refereed) papers presented at the 38th Conference of the School of Mathematics "G.Stampacchia" of the "E.Majorana" Centre for Scientific Culture of Erice (Sicily), held in Memory ofG. Stampacchia and J.-L. Lions in the period June 20 - July 2003. The presence of participants from Countries has greatly contributed to the success of the meeting. The School of Mathematics was dedicated to Stampacchia, not only for his great mathematical achievements, but also because He founded it. The core of the Conference has been the various features of the Variational Analysis and their motivations and applications to concrete problems. Variational Analysis encompasses a large area of modem Mathematics, such as the classical Calculus of Variations, the theories of perturbation, approximation, subgradient, subderivates, set convergence and Variational Inequalities, and all these topics have been deeply and intensely dealt during the Conference. In particular, Variational Inequalities, which have been initiated by Stampacchia, inspired by Signorini Problem and the related work of G. Fichera, have offered a very great possibility of applications to several fundamental problems of Mathematical Physics, Engineering, Statistics and Economics. The pioneer work of Stampacchia and Lions can be considered as the basic kernel around which Variational Analysis is going to be outlined and constructed. The Conference has dealt with both finite and infinite dimensional analysis, showing that to carry on these two aspects disjointly is unsuitable for both.

This book focuses on the tremendous development that has taken place recently in the field of of nondifferentiable nonconvex optimization. Coverage includes the formulation of optimality conditions using different kinds of generalized derivatives for set-valued mappings (such as, for example, the co-derivative of Mordukhovich), the opening of new applications (the calibration of water supply systems), and the elaboration of new solution algorithms (e.g., smoothing methods).

Optimization and optimal control are the main tools in decision making. Because of their numerous applications in various disciplines, research in these areas is accelerating at a rapid pace. “Optimization and Optimal Control: Theory and Applications” brings together the latest developments in these areas of research as well as presents applications of these results to a wide range of real-world problems. This volume can serve as a useful resource for researchers, practitioners, and advanced graduate students of mathematics and engineering working in research areas where results in optimization and optimal control can be applied.