The organisation of urban systems

We develop here a theory of the organization of cities and systems of cities as multilevel networks, including two main observable levels, where specific emergent properties can be observed. We use an evolutionary perspective, which is based on observations about the way cities co-evolve within urban systems, through a variety of social interactions. Empirical evidence of the corresponding patterns and processes is provided for three main styles of urbanization, exemplified in four different parts of the world