Paul Kerswill is Emeritus Professor of Sociolinguistics at the University of York, UK. His research focuses particularly on dialect and language contact resulting from migration. With Jenny Cheshire, Sue Fox and Eivind Torgersen, he has published “Contact, the Feature Pool and the Speech Community: The emergence of Multicultural London English” (Journal of Sociolinguistics). Heike Wiese is Professor of German in Multilingual Contexts and founder of the Centre “Language in Urban Diversity” at Humboldt-Universität in Berlin. Her 2012 monograph on Kiezdeutsch as a new German dialect received national and international media attention, and raised awareness of urban contact dialects as a legitimate part of the linguistic landscape.