Forthcoming in Rosalind Dixon and Tom Ginsburg, Research Handbook on Comparative Constitutional Law (Edward Elgar Publishing Ltd., 2010) A New Global Constitutional Order?

Accompanying the rise of new transnational legal rules and institutions intended to promote global economic integration are questions about the linkages between transnational legality and constitutional law. In what ways does transnational economic law mimic features of national constitutional law? Does transnational law complement in some ways or supersede in other ways what we typically describe as constitutional law? To these questions we can now add the following: are transnational rules and institutions a proper subject of study for comparative constitutionalists? This chapter makes a case for the incorporation of forms of transnational legality into comparative constitutional studies.1 Taking as its focus the regime of international investment law, I argue that an appreciation of the constitutional functions of transnational legality deepen understandings of how constitutional law develops within, across, and beyond national systems of law. More specifically, elements of transnational legality can help to explain the phenomenon of convergence and divergence in constitutional law. This expansion of the comparativist’s toolkit of resources, though challenging conventional understandings of constitutional law as grounded exclusively in states, better captures current developments