After occupying a research post at the Observatoire du Samusocial de Paris (Observatory of the Paris Samusocial, a humanitarian emergency service), Nicolas Oppenchaim is now a sociology lecturer at the Université François Rabelais in Tours. For his PhD thesis (titled Mobilité, socialisation et ségrégation : une analyse à partir des manières d’habiter des adolescents de zones urbaines sensibles, Laboratoire Ville, Mobilité, Transport (LVMT), Université Paris-Est Marne-la-Vallée, 2011), he studied the mobility practices of teenagers living in segregated neighbourhoods. His current work concerns homeless children and families.