I would like to use this preface to thank some persons and institutions
which have been important during the various stages of writing this
book. First of all, I am grateful to Kluwer Academic Publishers for
giving me the opportunity to write this book. I started writing the book
in 1998 while I was working at the Departament d'Economia i d'Historia
Economica at Universidad Autonoma de Barcelona, and continued the
writing job from september 1998 to september 2000 at the Departamento de
Economfa at Universidad Carlos III de Madrid. The book has been
completed while I was visiting the Department of Quantitative Economics
at the University of Maastricht from october 2000 to august 2001. I wish
to thank these three departments for their hospitality. The book has
improved substantially by comments and critique from the following
persons who have read parts of the manuscript: Geir Asheim, Eric van
Damme, Janos Flesch, Mari-Angeles de Frutos, Diego Moreno, Hans Peters,
Antonio Romero and Dries Vermeulen. I should also mention my discussions
with Peter Wakker about the decision-theoretic foundations of
noncooperative game theory, which have had an important impact on
various parts of the book. Finally, I wish to express my warmest
gratitude to my parents, my brother and my sister, and, last but not
least, to Cati, to whom I dedicate this book.