Concentric Zone Model

The concentric zone model, formulated by sociologist Ernest Burgess of the Chicago School in the 1920s, describes the city as a set of concentric rings of land use and social structure expanding outward from a central business district. Each ring — from the commercial core, through a transitional zone of factories and tenements, to successive rings of workers' homes, better residences, and commuters — represents a stage in the city's outward growth. Published in the 1925 volume The City, it was the first influential model of urban spatial structure and treated the city through the lens of human ecology, with zones competing and invading one another like species in an ecosystem.