Comparative analyses of a range of key issues related to unjustified enrichment, an important area of private law.Unjustified enrichment is one of the most intellectually vital areas of private law. However, little unanimity exists among civil-law and common-law legal systems about structuring this important branch of the law of obligations. This book analyses a range of key issues, considered both by a representative of a common-law, and a representative of a civil-law system. This approach illuminates both similarities or differences between systems, and what different systems can learn from each other. This will be valuable for academic analysis of the law and its development by the courts.Unjustified enrichment is one of the most intellectually vital areas of private law. However, little unanimity exists among civil-law and common-law legal systems about structuring this important branch of the law of obligations. This book analyses a range of key issues, considered both by a representative of a common-law, and a representative of a civil-law system. This approach illuminates both similarities or differences between systems, and what different systems can learn from each other. This will be valuable for academic analysis of the law and its development by the courts.Unjustified enrichment is one of the most intellectually vital areas of private law. However, little unanimity exists among civil-law and common-law legal systems about structuring this important branch of the law of obligations. This book analyzes a range of key issues which are considered respectively by a representative of a common-law, as well as a civil-law system. The approach highlights similarities and differences between systems, and what each can learn from the other.Part I: 1. Introduction David Johnston and Reinhard Zimmermann; Part II. Enrichment 'Without Legal Ground' or Unjust-Factor Approach?: 2. Unjust factors and legal grounds Sonja Meier; 3. In defence of unjust factors Thomas Krebsl³-