http://advances.sciencemag.org/content/1/1/e1400066 Settlement scaling and increasing returns in an ancient society Scott G. Ortman, Andrew H. F. Cabaniss, Jennie O. Sturm, Luís M. A. Bettencourt Science Advances 01 Feb 2015: Vol. 1 no. 1 e1400066 DOI: 10.1126/sciadv.1400066 The basic concept here is that the same rules for humans developing cities have not changed. This is because what cities provide requires changes in living styles, specialization in trades, and proximity to other people to provide these benefits. The sciencemag.org article is a good read but I also included the primary resource. For example: They compared data from ancient Mexican cites against modern counterparts. As a city's population doubles it expands to cover an additional 83% more space. True past and present. Demographics (status and wealth or resource control) reflected by size of domicile reflect the same underlying data in both modern and ancient cities.