He is Professor of Philosophy of Law at the University of Buenos Aires and a visiting professor of law at ITAM (Mexico). Directs the Program on Economic, Social and Cultural Rights of the International Commission of Jurists in Geneva. He has been visiting professor and guest at the University of Toulouse-Le Mirail (France), Carlos III (Madrid), Castilla-La Mancha, Deusto, Pablo de Olavide and Valencia (Spain), California-Berkeley (USA), Iberoamericana (Mexico) and Diego Portales (Chile), among others. His recent books include: Threshold of citizenship. The meaning of social rights in the constitutional welfare state (2006); Social rights in democratic debate (2006); The application of human rights treaties at the local level. The experience of a decade (1994-2005) (with Víctor Abramovich and Alberto Bovino, 2006) Not one step back. The prohibition of regressive social rights (2006). In this same Editorial is coauthor, with Víctor Abramovich, Los social rights as enforceable rights (2002, 2004).