Known currently as the "circulation of talent", or "exile of the learned", the nomadic nature of elites gave way to reflections on the mobility of highly-trained resources, on programs for the repatriation or organization of diasporas, and on the generation of endogenous capacities that make it possible to overcome prosperity gaps between the countries of the South and those of the North. These focuses, as novel as they have been, have not made it possible to respond to all of the questions raised by the brain drain and brain gain ; nor to document their quantitative features, their current characteristics, nor their repercussions on the structuring of research communities.

Publication of the book entitled "Fuga de cerebros, movilidad académica y redes científicas" (in English, The Brain Drain, Academic Mobility, and Science Networks ) edited by Sylvie Didou Aupetit and Etienne Gérard , with articles by researchers from Argentina, Brazil, Costa Rica, Mexico, Venezuela, France, Canada, and the United States, seeks to reflect on previously ill-defined points linked to the unequal exchange of grey matter, without underestimating its positive effects in terms of individual freedom of movement, the structuring of networks, and the transfer of knowledge. With the intention of bringing together thought on this issue, the authors have taken a new look at the notion of "the circulation of skills" and its multiple opposed manifestations of loss or of compensation. They are interested in the causes and consequences of the international circulation of students, academics, and researchers.

Such spatial mobility, in order to obtain academic degrees or for professionalization, is of interest not only because it is in a phase of asymmetric growth; it also has repercussions on the establishment of academic and scientific teams within sending and receiving countries: it determines their insertion and modes of inclusion in physically present and virtual disciplinary or strategic networks, with varying degrees of formality and duration, as well as their intellectual and tactical connections with similar teams from outside. It is, therefore, part of the growing globalization of the scientific field and, in the countries of the South, of its silent internationalization through training and collaboration of academic leaders abroad. It also has an influence that deserves consideration, in the circulation of knowledge between countries of the same region or between different regions.

Finally, the different authors have sought to gauge the respective contributions of public policies at national and regional levels, and of the social and disciplinary logics of work and training, in the emergence of state-of-the-art technology, in part free of territorial considerations, in both academia and science.

By Sylvie Didou Aupetit

Sylvie Didou is a full-time researcher at the Centro de Investigación y Estudios Avanzados of the Instituto Politécnico Nacional (CINVESTAV-IPN) – didou@cinvestav.mx . Etienne Gérard is a researcher at the Instituto de Investigación para el Desarrollo (IRD) in Research Unit 105 "Knowledge and Development" in France – gerardeti@yahoo.fr