describes the peculiar American geography, where the inner city is poor while suburbs are wealthy; the inverse is the norm elsewhere. It assumes an isotropic plane – an even, unchanging landscape. Physical features – land may restrict growth of certain sectors; hills and water features may make some locations unusually desirable for residential purposes. Commuter villages defy the theory, being a distant part of the commuter zone. Decentralization of shops, manufacturing industry (see Industrial suburb), and entertainment. Urban regeneration and gentrification – more expensive property can be found in formerly 'low class' housing areas. Many new housing estates were built on the edges of cities in Britain. It does not address local urban politics and forces of globalization. The model does not fit polycentric cities, for example Stoke-on-Trent. See also 100 percent corner Core frame model Distance decay Friction of distance Multiple nuclei model Sector model (Hoyt model) Transect (urban) Tobler's first law of geography Urban structure Johann Heinrich von Thünen's ring model References External links City layout models