This book contains a modern treatment of production economics from a dual perspective, with special emphasis on recent developments. Results that were scattered throughout professional journals and monographs are now gathered into an integrated approach using a common notation. The book prepares the reader to apply the tools of the dual approach to real world problems and data sets. Particular care has been devoted to choosing topics for discussion that achieve this goal. Throughout the book there are worked examples and exercises, which are geared toward developing the reader's facility in using modern developments in production economics. Separate chapters are devoted to production, cost, and profit functions. Other topics include flexible functional forms, aggregation across inputs and outputs using the theory of separable structures, aggregation over economic optimizing firms, the representation of multioutput technologies, and the analysis and measurement of technical change from both a primal and a dual perspective.