Bob Goodin is Distinguished Professor of Philosophy at Australian National University. He is Founding Editor of the Journal of Political Philosophy and was General Editor of the eleven-volume series of Oxford Handbooks of Political Science. Goodin's work centres on political theory and public policy. He is co-author of, most recently, On Complicity and Compromise and Explaining Norms, both published by OUP in 2013. Kai Spiekermann is Associate Professor of Political Philosophy at the London School of Economics. Among his research interests are normative and positive political theory, philosophy of the social sciences, social epistemology and environmental change. He is particularly interested in applying formal methods, computational simulations, and experiments to problems in political philosophy. His recent publications have focused on mechanisms of norm avoidance, strategic ignorance and moral knowledge, on information aggregation, jury theorems and epistemic democracy, and on reductionism and holism in the social sciences.