This book contains the latest insights into the theory of Giffen goods. In the past, surprisingly few goods could be categorized as "Giffen." This may be because of a lack of understanding of the character of these goods. Therefore, the theories explained in this book may also produce a solid basis for further empirical research in the field. Experts throughout the world have contributed to this book, which predominantly pursues a mathematically rigorous approach. It may be used by researchers in the field of fundamental economics and in graduate-level courses in advanced microeconomics.