of the state or political realists who deny that considerations of justice apply outside of the boundaries of the state. Borjas, George. 2001. Heaven's Door: Immigration Policy and the American Economy. Princeton University Press; Hendrickson, David C. 1992. "Migration in law and ethics: A realist perspective." In Free Movement: Ethical issues in the transnational migration of people and of money. Eds. Brian Barry and Robert E. Goodin. University Park, Pennsylvania: The Pennsylvania University Press, pp. 213-231). It is also common in popular discussion and in public policy. Contemporary political theorists usually reject the extreme position that there are no duties to people outside of our political community. Rather, they argue about the extent of our obligations, for example whether we are committed to a sufficiency standard that entitlesand Justice: Diverse Ethical Perspectives, eds., David Miller and Sohail H. Hashmi, Princeton, NJ: Princeton University Press; Meilaender, Philip. 2001. Toward a Theory of Immigration. Basingstroek: Palgrave; Miller, David. 2007. National Responsibility and Global Justice. New York: Oxford University Press. 11 Walzer, Michael. 1983. Spheres of Justice. New York, NY: Basic Books. 12 Wellman, Kit. 2008. "Immigration and Freedom of Association." Ethics 119: 109-141. 13 Pevnick, Ryan. 2011. Immigration and the Constraints of Justice. New York, NY: Cambridge University Press. THE IMPLICATIONS OF MIGRATION THEORY FOR DISTRIBUTIVE JUSTICE 59 GLOBAL JUSTICE : THEORY PRACTICE RHETORIC (5) 2012 whatever obligations we owe to people as fellow human beings, these obligations are stronger when we have played a harmful causal role in their fate. It stresses the importance of institutions