Private international law in the nexus of European integration: A study in comparative federalism.

Summary European integration has resulted in a paradigm shift for private international law in Europe. The altered context of European federalism, comparable in its impact on private international law with the federal context of the United States, leads first to a constitutional framework for the content of the rules of private international law that the member states or the European legislature adopt, and thus for the normative competences of the member states. This framework results from the interpretation by the Court of Justice and the Supreme Court of several provisions of the European Union treaties and the United States Constitution respectively. The interpretation adopted, which in the United States in particular has fluctuated greatly throughout its history, determines the form of federalism of the two unions. The second result of the altered context is a transformation of the function of private international law rules. The attribution of competence in private international law to the Union, an aspect neglected by the European legislator, has reinvested this area of law with its function of distributing competence among states and has, moreover, invested it with a systemic function: the configuration of the legislative system of European private international law determines the form of legislative competition among states and their ability to produce legislative externalities. Influencing the very nature of the law of the states and the implementation within them of the principle of the rule of law and democracy, the European legislator thus also defines the form of European federalism within the constitutional margins set by the Court of Justice.