He is author of Elements of Justice (Cambridge, 2006), Rational Choice and Moral Agency (Princeton, 1995), co-author of Social Welfare and Individual Responsibility (Cambridge, a “For & Against” book with Robert Goodin) and editor of a volume on Robert Nozick in the Cambridge University Press "Contemporary Philosophy in Focus" series. He also co-edited Environmental Ethics: What Really Matters, What Really Works (Oxford) with Elizabeth Willott; a second edition of this book appeared in 2011. His first book, The Limits of Government: An Essay on the Public Goods Argument (Westview, 1991), combined his interests in moral philosophy and economic analysis.
He has published in many journals, including the Journal of Philosophy, Ethics, and Political Theory. Over fifty of his articles have been (or are in the process of being) reprinted, including Spanish, Portuguese, Mandarin, Turkish, Italian, Romanian, Czech, Slovak, and German translations. Thirteen of his essays (one previously unpublished, on Peter Singer's approach to moral theory) were published by Oxford Press as Person, Polis, Planet in 2008. A Brief History of Liberty (Wiley-Blackwell), with co-author Jason Brennan appeared in 2010. He is now working on Markets In Education (Oxford) with Harry Brighouse.