Transnational linkages and flows occur today on a massive scale, but the specific nature and quality of the phenomena that travel has received relatively little attention in the social sciences. In this research program it is precisely the quality, nature and significance of the various phenomena that travel that will be explored and compared. The phenomena to be focused upon are both material and immaterial, and are referred to as substances and concepts .
Substance refers to the material dimension of transnational flow.
Furthermore, in view of the comparative objective, persons are included as a particular category of substance subject to transnational flow. This is relevant not only in relation to various forms of legal and illegal international labour migration, but also in relation to phenomena such as transnational adoption, political refugeeness, labour migration and postal brides . In this project all such immaterial phenomena will be referred to as concepts . Concepts thus refer to the dimension of transnational flows that includes ideas, terms, programmes notions or dichotomies that serve to inform both the ordering of, and the order of things at local levels. The program facilitates the opportunity to explore some common dimensions inherent in these different ethnographic cases.