Preface

Carlos has conducted influential research in mathematical economics, advancing our understanding of topics such as: The representability of preferences by utility functions; the relationship between the non-cooperative notion of general economic equilibrium and various cooperative solution concepts; and the implications of differential information for general equilibrium analysis.Some of this research was done in collaboration with his students.The enthusiastic dedication of Carlos to advising and mentoring was so impactful that Carlos effectively created a school with his intellectual imprint at U. Vigo, with ramifications at U. Carlos III de Madrid, U. Salamanca, and U. Porto.Carlos nurtured the mathematical economics community in many ways.He served as an associate editor of Economic Theory and Journal of Mathematical Economics, organized numerous workshops and conferences, and brought together scholars from diverse backgrounds to foster dialogue among them.He also made more intangible contributions -we have all witnessed and benefitted from his legendary generosity and hospitality on many occasions.Given the important contribution of Carlos to U. Porto -teaching mathematical economics in the Ph.D. program and being a mentor to colleagues and students interested in economic theory -we organized a small workshop at U. Porto to celebrate his 70 th birthday.