We would now like to account for the behavior of collective growth in a system of cities and the pattern of relative fluctuations. Specifically, we would like to understand at a fundamental level the slowness and persistence of these deviations from scaling as well as get a handle on their typical magnitudes.

To address the issues our cities face in the twenty-first century we need both, seeing the world as quantum physics does, understanding that light can be both an individual particle and a collective wave. To thrive and adapt, cities need to enhance both our individual and our collective nature.