Urban Addendum

The Central Place Theory was proposed in 1933 by Walter Christaller. In his attempt to see if there are rules that determine the size, number and distribution of towns, he developed this model of how cities are spaced out in relation to each other.  In order his model to be valid he made three assumptions: 1) the towns have similar purchasing power n all directions and  are located in an Euclidean, isotropic way 2) there is a well developed transportation network that connects the smaller cities with the central place (a central city that serves the rest cities of the network with goods and services) 3) The products are been purchased from the nearest central place and all the central places have similar demand and none is making any excessive profit. An example f this model can be a central located city that supplies with goods the satellite cities that are located around. These cities do not consume all the manufacturing goods but distribute them  locally, to retail distributors  in smaller towns that are hexagonally located around them. However, the CPT theory  has been criticized as it does not take into consideration the temporal aspect in the development of central places and it doesn't give any information about the market's structure. According to Krugman (1995) is more a way to organize data about the urban systems in space rather and not an integrated economic theory based on location.