The central hypothesis of this project is that socio-economic, socio-demographic, ethnic and cultural diversity can positively affect social cohesion, economic performance and social mobility of individuals and groups. A better social cohesion, higher economic performance and increased chances for social mobility will make European cities more liveable and more competitive. In this period of long-term economic downturn (or sometimes even crisis) and increasing competition from countries elsewhere in the world (e.g. China, India), it is important to find out how and under which circumstances European's urban diversity can be turned into social and economic advantages. Many current urban policies lack a positive view on urban diversity, because they generally focus on the negative aspects of diversity, such as intolerance, racism, discrimination and insecurity. New policies, instruments and governance arrangements are needed, and sometimes they already exist. We have to find out how they have become successful and how they can be implemented elsewhere. When we acknowledge the hyper-diversity of our urban societies, we also have to acknowledge that these societies cannot flourish from standard or general approaches aiming at, for example, economic growth or better housing or more liveable neighbourhoods. Increasingly, more diverse, more tailored arrangements are needed, arrangements that have an eye for hyper-diverse cities and communities. As a result of the project, new and innovative policy instruments and governance arrangements will be suggested that (a) recognise urban diversity as a positive aspect; (b) increase interaction and communication between the diversity of groups in urban society; and (c) increase participation to satisfy the needs of the communities. The project thus aims at finding out how urban diversity influences three core issues: social cohesion, economic performance and social mobility and how governance arrangements help to strengthen this.