Rainer Wehrhahn is professor of urban geography and population and migration studies at Kiel University. Jörg Pohlan is professor of urban development and quantitative methods of urban and regional research at the HafenCity University, Hamburg. Christine Hannemann is professor of architectural and housing sociology at the University of Stuttgart. Frank Othengrafen is assistant professor in regional planning and governance at Leibniz Universität Hannover. Brigitta Schmidt-Lauber is professor of European Ethnology at the University of Vienna.