Central place theory, developed by the German geographer Walter Christaller as his doctoral dissertation, Central Places in Southern Germany in 1933, was a highly influential set of models widely used to describe and analyze urban hierarchies in the mid 20th century.

Essentially, central place theory is a model of city systems that posits them as retail centers (central places) that distribute goods and services to their surrounding hinterlands. Like many models of spatial analysis, it assumes a featureless isotropic plain in which population density and transport costs are equal in all directions. Each good has a threshold, or minimum market size, as well as a range, or maximum distance consumers will travel to purchase it (Figure 1). The size of a given good's range and threshold ...