The Concentric Zone model is a model of the internal structure of cities in which social groups are spatially arranged in a series of rings. The Concentric Zone model was the first to explain the distribution of different social groups within urban areas. It was originally based off Chicago (although the model does not apply well to Chicago today). The model was created in 1923 by E.W. Burgess, Robert Park, and Roderick McKenzie?. The idea behind this model is that the city grows outward from a central area in a series of rings. The size of the rings may vary, but the order always remains the same. This model suggests that the social structure extends outwards from the central business district, meaning that the lower classes live closer to the city center, while the upper classes live farther from the city center because they can afford the commute. Also, as you get further away from the city density decreases. The rent tends to increase as you get further away from the CBD and residents are more likely to rent near the center. As you get further away from the CBD it is more likely that you will find condominiums. Indianapolis is a city that can be applied to the concentric zone model today. That is because more people rent near the CBD than away from it. However, this model has its weaknesses. It does not take into account any physical barriers and it does not take into account gentrification- which may occur in these cities.

An important feature of this model is the positive correlation of socio-economic statuts of households with distance from the CBD — more affluent households were observed to live at greater distances from the central city. Burgess described the changing spatial patterns of residential areas as a process of "invasion" and "succession". As the city grew and developed over time, the CBD would exert pressure on the zone immediately surrounding it (the zone of transition). Outward expansion of the CBD would invade nearby residential neighborhoods causing them to expand outward. The process was thought to continue with each successive neighborhood moving further from the CBD. He suggested that inner-city housing was largely occupied by immigrants and households with low socio-economic status. As the city grew and the CBD expanded outward, lower status residents moved to adjacent neighborhoods, and more affluent residents moved further from the CBD.

Burgess's work is based on the bid rent curve. This states that the concentric circles are based on the amount that people will pay for the land. This value is based on the profits that are obtainable from maintaining a business on that land. The center of the town will have the highest number of customers so it is profitable for retail activities. Manufacturing will pay slightly less for the land as they are only interested in the accessibility for workers, 'goods in' and 'goods out'. Residential land use will take the surrounding land.

Problems with the Concentric Zone Model

The model has been challenged by many contemporary urban geographers. Firstly, the model does not work well with cities outside the United States, in particular with those developed under different historical contexts. Even in the United States, because of changes such as advancement in transportation and information technology and transformation in global economy, cities are no longer organized with clear "zones" (see: Los Angeles School of Urban Analysis).
• It assumes an isotropic plain - an even, unchanging landscape
• Physical features - land may restrict growth of certain sectors
• Commuter villages defy the theory, being in the commuter zone but located far from the city
• Decentralization of shops, manufacturing industry, and entertainment
• Urban regeneration and gentrification - more expensive property can be found in '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 work well for cities which are essentially federations of similar sized towns, for example Stoke-on-Trent?

The Different Rings of the Concentric Zone Model

1) Central Business District (CBD)- This area of the city is a non-residential area and it’s where businesses are. This area s called downtown in the U.S. and city center in Europe. This area has a developed transportation system to accommodate commuters coming into the CBD. Also, due to the high land cost in this area, a lot of sky scrapers are built in order to take full advantage of that land. Most government institutions, businesses, stadiums, and restaurants chose this area to build on due to its accessibility.
2) Zone of Transition- the zone of transition contains industry and has poorer-quality housing available. Immigrants, as well as single individuals, tend to live in this area in small dwelling units, frequently created by subdividing larger houses into apartments. Most people in this area rent.
3) Zone of the working class- This area contains modest older houses occupied by stable, working class families. A large percentage of the people in this area rent.
4) Zone of better residence- This zone contains newer and more spacious houses. Mostly families in the middle-class live in this zone. There are a lot of condominiums in this area and residents are less likely to rent.
5) Commuter’s Zone- This area is located beyond the build-up area of the city. Mostly upper class residents live in this area. This area is also known as the suburbs in the United States.

Other Names for the Concentric Zone Model

• The Burgess Model
• The Bull's Eye Model
• Concentric Ring Model
• Concentric Circles Model