Bijuralism or multijuralism - the presence of two or more legal systems in one legal order - is a widespread phenomenon, but one that has received very little scholarly attention. This is surprising once we recognize that problems associated with bi- or multijuralism appear whenever contracting parties to a transaction are located in jurisdictions that have different legal systems. These problems are set to multiply with globalization and other forms of economic integration such as the European Union. Meanwhile, the "solutions" essayed to address these issues also grow. The contributions presented here are not "traditional" Law and Economics papers in that they do not offer an economic analysis of the law and of its efficiency (in economic terms), but they all contain the necessary economics to elucidate and understand some of the problems encountered when legal systems are "forced" to interact. As such, the volume will be accessible to both lawyers and economists alike.