Introduction Vicki C. Jackson and Mark Tushnet; Part l. Paradigms of Proportionality: 1. Proportionality and rationality Robert Alexy; 2. Proportionality outside the courts, with special reference to popular and political constitutionalism Frank I. Michelman; 3. Is the structure of human rights practice defensible? Three puzzles and their solution Mattias Kumm; 4. Proportionality and absolute rights Grégoire Webber; Part ll. Proportionality and the United States: 5. Constitutional law and proportionality: the administrative origins of constitutional rights and how they shaped global constitutionalism Moshe Cohen-Eliya and Iddo Porat; 6. US constitutional law, proportionality, and the global model Kai Moller; 7. Beyond proportionality: thinking comparatively about constitutional review and punitiveness Jacco Bomhoff; 8. Proportionality and equality Vicki C. Jackson; 9. Proportionality and stare decisis - proposal for a new structure Vlad Perju; Part lll. Extending the Reach of Proportionality and Equality: 10. Positive and horizontal rights: proportionality's next frontier or a bridge too far? Stephen Gardbaum; 11. Proportionality, reasonableness, and economic and social rights Katherine G. Young; 12. In praise of casuistry: making hard cases easier David Beatty; Part lV. Thoughts for the Future: Of Scepticism and Research Agendas: 13. Making easy cases harder Mark Tushnet; 14. A research agenda for the future Aharon Barak.