Vivacity in changing economies: cities are engines of economic growth and of places where innovations emerge. Yet some cities have greater economic success than others. All over Europe we find cities with rapid economic growth and a strong decline, as well as cities with a growing economy. These trajectories as expressions of vitality are closely related to population dynamics in terms of growth or contraction. We need a better understanding of the factors that drive the economic success or failure of cities. We need to know how innovation moves the size and segmentation of labor markets and how they change migration models in response to these changes. Furthermore, new strategies are needed to combine the creation of economic opportunities with social innovation in order to create open, inclusive, cohesive and more liveable cities. In short, we must find new ways to achieve and sustain socio-economic vitality and equality in cities with evolving economies.