Any network of towns and cities, and their hinterlands, which can be seen as a system, since it depends on the movements of labour, goods and services, ideas, and capital through the network. Freestone et al. (2003) Tijdschrift 94, 2 illustrate the way Australian urban systems reflect broader economic, demographic, and social trends. Abdel-Rahman (2002) J. Reg. Sci. 42 links the structure of an urban system with income disparities: economies that are dominated by a large metropolis, with a number of low-technology cities, will have large income disparities.