The idea of the line of research presented in this book emerged from a conversation in the French foothills of the Pyrenees in April 1996. The prevailing separation between the theory of social choice, the theory of fair allocation, and public economics seemed to call for a unified approach that would construct social preferences similar to the first, relying on fairness concepts from the second, and derive policy conclusions for the third. It took more time than we expected to transform this idea into a recognized theory, and we are pleased to acknowledge the support and constructive influence of many colleagues and friends. The late Louis Gevers, who had worked himself at the intersection of social choice and fair allocation, was the first to express interest and provide encouragements. Our debt to him is immense. Peter Hammond, Philippe Mongin, Juan de Diós Moreno-Ternero, Erwin Ooghe, Erik Schokkaert, Yves Sprumont, Kotaro Suzumura, and Koichi Tadenuma were very helpful at different stages of our work and became coauthors and partners in this research. We are also deeply indebted to Eric Maskin, John Roemer, and John Weymark, who commented on and discussed several of our early works on this topic. Their support was both helpful and encouraging. The interest shown by students who made their own contribution to this direction of research, Efthymios Athanasiou and Giacomo Valletta, was a great reward.