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By the end of this lesson, students will be able to (per CED LO PSO-6.D):
- Explain the internal structure of cities using various models and theories (per LO PSO-6.D).
- Describe the Burgess concentric-zone model and identify its five rings (per EK PSO-6.D.1).
- Describe the Hoyt sector model and explain how transportation corridors shape its pie-wedge geometry (per EK PSO-6.D.1).
- Describe the Harris and Ullman multiple-nuclei model and identify examples of polycentric cities (per EK PSO-6.D.1).
- Describe the galactic city model and the role of edge cities (per EK PSO-6.D.1).
- Apply bid-rent theory to explain land-value patterns around a central business district (per EK PSO-6.D.1).
- Describe the Latin American, Southeast Asian, and Sub-Saharan African urban models and explain why separate models are needed (per EK PSO-6.D.1).
- Apply Skill 1.E by comparing the strengths, weaknesses, and limitations of each model in specified contexts.
Key Concepts
Per EK PSO-6.D.1, the CED names eight distinct tools for explaining internal urban structure. Unlike Lesson 6.4, where four principles explained different questions, here all eight tools answer the same question in different ways. That is why Skill 1.E is paired with this topic: students must compare strengths, weaknesses, and limitations rather than simply recite each model.
Skill 1.E requires comparative analysis
Skill 1.E is not a recall skill. The CED states it as: "Within a given context, account for the strengths, weaknesses, and limitations of various geographic models and theories." The exam regularly asks students to evaluate which model best fits which city, and to explain why no single model fits every case. That is the pedagogical purpose of EK PSO-6.D.1 naming eight tools rather than one.
Three common dimensions for comparing the models
- Geometry: rings (Burgess), wedges (Hoyt), nodes (Harris-Ullman), spines (Latin America), tripartite (Africa).
- Era and context: 1920s industrial (Burgess, Hoyt), post-war suburban (Harris-Ullman), automobile and edge-city (galactic), colonial-origin (Latin America, Southeast Asia, Africa).
- Assumptions: single versus multiple CBDs, flat-plain assumption, Western industrial versus colonial historical path.
Burgess Concentric Zone Model (1925)
Five concentric rings radiating from a single CBD
Ernest Burgess proposed the concentric-zone model in 1925 as part of the Chicago School of urban sociology, based on observations of 1920s Chicago. Land use arranges itself in five rings around a single central business district. Each ring has a distinct social and functional character.
The five rings: (1) Central Business District with retail, offices, and civic buildings. (2) Zone of transition with older factories, warehouses, and deteriorating housing occupied by recent immigrants and the urban poor. (3) Zone of working-class housing, second-generation residents who escaped the zone of transition. (4) Zone of middle-class housing, single-family homes. (5) Commuter zone, suburban rings served by rail.
Applying Skill 1.E to Burgess
Burgess is a valuable baseline because it introduces the idea that urban land uses have predictable spatial patterns. Its weaknesses become obvious when applied outside its context: it assumes a single CBD, which fails in Los Angeles; it ignores transport corridors, which Hoyt captured; it takes 1920s Chicago segregation as natural, which hides the role of racial covenants, redlining, and zoning policy in producing those rings. When an FRQ asks for strengths and limitations, name at least one of each.
Hoyt Sector Model (1939)
Pie-wedge sectors radiate out along transport corridors
Homer Hoyt, an economist for the US Federal Housing Administration, revised Burgess in 1939. He argued that land uses extend outward from the CBD in pie-wedge sectors that follow transportation corridors: rail lines, highways, or rivers. Once a high-rent residential sector is established along a desirable corridor (for example, along a scenic waterfront or a commuter rail line), new high-rent housing extends outward along that same corridor rather than re-forming as a ring.
Hoyt used rent data from 142 US cities in the 1930s. The model captures the observed pattern that Chicago's Gold Coast, Philadelphia's Main Line, and Boston's Beacon Hill axis extend outward along transport routes as wedges rather than rings.
Hoyt versus Burgess
Hoyt does not replace Burgess; it refines it. Hoyt still assumes a single CBD at the center. His innovation is recognizing that transportation corridors deform Burgess's perfect rings into wedges. On the AP exam, a common Skill 1.E comparison is: Burgess captures distance-decay of land value; Hoyt adds directional inheritance along transport corridors. Both share the same blind spot: they assume one CBD.
Harris-Ullman Multiple-Nuclei Model (1945)
Multiple specialized nuclei rather than one center
Chauncy Harris and Edward Ullman published the multiple-nuclei model in 1945. They argued that modern cities have grown too large and too functionally specialized to fit into a single CBD pattern. Instead, a city contains several nuclei, each anchored by a specialized activity: a downtown retail district, a separate industrial zone, an outlying business district, a port cluster, a university district, an airport node, and so on.
Their four organizing principles: (1) certain activities require specialized facilities (a port needs water access); (2) similar activities cluster for agglomeration economies; (3) incompatible activities repel each other (heavy industry and high-rent housing); (4) some activities cannot afford CBD rents. The model describes rather than predicts, which makes it more flexible but less mathematically tidy.
Los Angeles as the canonical example
Harris-Ullman is the AP go-to example for polycentric cities. Los Angeles has a downtown CBD but also specialized nuclei in Century City, Hollywood, Beverly Hills, Long Beach (port), the LAX airport district, the San Fernando Valley, Santa Monica, and Pasadena. No single center dominates. Houston, Dallas-Fort Worth, and Atlanta display similar multi-nuclei structures.
Galactic / Peripheral City Model
Edge cities on beltways replace the old CBD
The galactic city model (sometimes called the peripheral model) updates Harris-Ullman for the post-automobile era. Building on the work of Chauncy Harris and of journalist Joel Garreau's Edge City (1991), the model describes how US metropolitan areas after about 1970 began to develop edge cities on suburban beltways. An edge city is a large cluster of office space, retail, and hotels that sits at a highway interchange far from the traditional CBD, typically around a regional shopping mall or an airport.
Classic edge-city examples: Tysons Corner, Virginia (outside Washington DC); King of Prussia, Pennsylvania (outside Philadelphia); Schaumburg, Illinois (outside Chicago); the Galleria in Houston. Each has more office space than many mid-sized downtowns.
Why the galactic model matters for Skill 1.E
The galactic city model directly illustrates Skill 1.E. The strength is that it captures something Burgess, Hoyt, and even Harris-Ullman missed: the decline of the traditional CBD in many US cities and the growth of edge-city rivals. The limitation is equally sharp: it describes a specific national context (US automobile suburbanization) and does not transfer cleanly to cities in countries with different land-use policy, fuel prices, or transit systems. When a student is asked to evaluate the galactic model for Paris or Tokyo, the expected answer is that it is a poor fit.
Bid-Rent Theory
Land value declines with distance from the CBD
Bid-rent theory is a mathematical formalization of why land near the CBD is so expensive. Different land users have different willingness to pay for central locations. Retail and office users can afford the highest rents because foot-traffic and accessibility generate high revenue per square meter. Housing bids less. Agriculture bids least. The user with the highest bid captures each location.
Plotted on a graph, the bid-rent curves of different users cross at predictable distances from the CBD. That is why CBDs contain skyscrapers (retail and office), middle rings contain housing, and outer rings contain farms or open space. Bid-rent theory is the economic engine that drives Burgess's rings.
Bid-rent and the other models
Bid-rent is not a separate geometric model like Burgess or Hoyt. It is the economic mechanism underneath them. Burgess's rings exist because bid-rent curves produce concentric distance-decay of land value. Hoyt's wedges exist because transport corridors locally distort the bid-rent surface. Harris-Ullman's nuclei exist because some users (ports, universities) have bid-rent functions that are not centered on the CBD. On the AP exam, a common Skill 1.E question asks students to show how bid-rent explains why a particular model's geometry emerges.
Latin American City Model (Griffin-Ford, 1980)
Elite spine from colonial CBD; peripheral disamenity zones
Ernst Griffin and Larry Ford published the Latin American city model in 1980. It captures a distinct colonial-origin pattern common in Mexico, Central America, and much of South America. At the center is a colonial-era CBD organized around a central plaza, cathedral, and administrative buildings. Extending outward from the CBD is an elite spine: a tree-lined commercial boulevard with high-amenity shopping, embassies, and wealthy residential districts.
Zones outward from the CBD: (1) zone of maturity, older middle-class housing in colonial-era neighborhoods; (2) zone of in-situ accretion, transitional mixed-quality housing being improved incrementally by residents; (3) disamenity zone, peripheral squatter settlements on unwanted land (steep slopes, floodplains) that lack legal tenure and formal infrastructure. Known locally as favelas (Brazil), colonias populares (Mexico), or villas miserias (Argentina).
Why a separate Latin American model exists
The Latin American model exists in EK PSO-6.D.1 precisely because Burgess, Hoyt, Harris-Ullman, and the galactic model fail to describe Latin American cities. The colonial-era grid and plaza; the paradox of wealth close to the center rather than in distant suburbs; the dense ring of self-built housing on the periphery; all of these invert the US pattern. Skill 1.E expects students to explain this inversion rather than force a US model onto a Latin American city.
Southeast Asian City Model (McGee, 1967)
No single CBD; functions cluster around an old colonial port
Terence McGee published the Southeast Asian city model in 1967, based on studies of port cities across Indonesia, Malaysia, the Philippines, Thailand, and Vietnam. Unlike Western models, the McGee model has no single central business district. Instead, several specialized zones organize around an old colonial port.
McGee's zones: (1) the old colonial port as the historical anchor; (2) an alien commercial zone, often dominated by a Chinese-heritage merchant community; (3) a government zone inherited from the colonial administration; (4) a Western commercial zone of banks and international business; (5) mixed land-use residential areas; (6) peripheral market-gardening zones that feed the city. Suburban squatter settlements appear on the edge, similar to Latin America's disamenity zones.
Why Southeast Asian cities need their own model
Southeast Asian cities share with Latin America a colonial-origin CBD, but the coastal port is the organizing anchor rather than a plaza. The ethnic commercial zone (often Chinese-heritage, as in Jakarta's Glodok, Manila's Binondo, or Bangkok's Yaowarat) is a distinctive feature that Western models do not include. McGee's recognition of a multi-ethnic commercial structure is one of the earliest explicit applications of ethnic geography to urban-form modeling.
Sub-Saharan African City Model
Three CBDs, ethnic neighborhoods, mining or manufacturing ring
Geographer Harm de Blij and others have proposed variants of a Sub-Saharan African city model. Its defining feature is three distinct central business districts: (1) a colonial CBD of European-built office and administrative towers; (2) a traditional CBD of older African trading quarters; (3) a market zone (periodic or permanent) where informal commerce concentrates. Surrounding the triple CBD are ethnic neighborhoods, a mining or manufacturing ring, and peripheral squatter settlements.
Examples: Nairobi (Kenya), Lagos (Nigeria), Kinshasa (Democratic Republic of the Congo), Accra (Ghana), Johannesburg (South Africa, with additional apartheid-era segregation overlays). The tripartite CBD reflects the layered colonial and pre-colonial history of urban development in the region.
What the African model teaches
The African model is the EK's clearest demonstration of why a single Western model is insufficient. Sub-Saharan African urban form is shaped by pre-colonial trading networks, European colonial overlay, post-independence rural-to-urban migration, and ongoing squatter-settlement growth. Compressing all of this into Burgess's five rings would lose critical detail. Skill 1.E expects students to name specifically what each model captures and what it misses.
Country Case Studies
Four cities, four different model fits — illustrating why the CED names so many tools.
Chicago, United States · Burgess Origin
Chicago is where Burgess first described the concentric-zone pattern in 1925. The Loop remains the CBD; the old zone of transition between the Loop and the South and West Sides was studied intensely by the Chicago School. Modern Chicago has also evolved toward Hoyt-style sectors (the North Shore Gold Coast) and galactic-model edge cities (Schaumburg, Naperville). No single model suffices today.
Country page →Los Angeles, United States · Multiple-Nuclei Poster Child
Los Angeles is the textbook AP example for Harris-Ullman. Downtown LA is a CBD, but so are Century City, Hollywood, Beverly Hills, Long Beach Port, LAX, Santa Monica, and the San Fernando Valley. The region also exhibits strong galactic-model edge-city patterns along the 405 and 101 beltways. Burgess and Hoyt fail here; multiple nuclei and the galactic model apply.
Country page →
Mexico City, Mexico · Griffin-Ford in Practice
Mexico City closely matches the Griffin-Ford Latin American model. The colonial CBD centers on the Zocalo plaza and Metropolitan Cathedral. Paseo de la Reforma forms the elite commercial spine extending northwest. Zones of maturity, in-situ accretion, and peripheral colonias populares surround this core. Districts such as Iztapalapa display the disamenity-zone pattern.
Country page →
Jakarta, Indonesia · McGee Southeast Asian Model
Jakarta displays the McGee model clearly. Sunda Kelapa is the old colonial port. Glodok is a Chinese-heritage commercial zone. Merdeka Square anchors the government zone inherited from Dutch colonial administration. Modern Sudirman-Thamrin is the Western commercial zone. Peripheral kampung settlements and squatter communities ring the city. Burgess and Hoyt do not fit; McGee does.
Country page →Discussion Questions
- Apply Skill 1.E: pick the large city nearest to your school. Which of the eight models in EK PSO-6.D.1 best explains its structure, and why? Equally important: which model fails to capture, and what is missing?
- Compare Burgess and Hoyt directly. What is one strength of Hoyt over Burgess? What is one limitation that both share? Cite Skill 1.E.
- The galactic city model is strongly US-centric. Name one strength it has for describing Washington DC and one limitation it has for describing Paris. What feature of US policy makes this model less transferable?
- Bid-rent theory is not a geometric model, yet EK PSO-6.D.1 includes it. Explain how bid-rent theory provides the economic mechanism that produces Burgess's rings and Hoyt's wedges.
- Why does EK PSO-6.D.1 name three region-specific models (Latin America, Southeast Asia, Africa) rather than one universal one? What does the exam expect a student to demonstrate with this plurality?
Classroom Activities
Model Fit-Check
Pairs pick a large world city (from a provided list of 20 spanning all continents). They map its structure against each of the eight EK PSO-6.D.1 tools and vote on the single best-fitting model. They write a 150-word justification that explicitly invokes Skill 1.E by naming at least one strength and one limitation of their chosen model for that city.
Model Remix
Small groups invent a new urban model for a specific cultural context not covered by the eight CED tools (for example, a Gulf-state oil city such as Dubai or Doha, or a Siberian resource city such as Yakutsk). They must name at least three distinctive zones and explain why existing models fail. Groups present their model and receive Skill 1.E critique from classmates on its strengths and limitations.
Vocabulary
Standards Alignment
Draft alignment — pending educator review. AP HG codes correspond to the official College Board Course and Exam Description (Effective Fall 2020, V.1). Statements below are paraphrased in CountryReports' own voice; refer to the College Board's published CED for verbatim wording.
Suggested Skill
Enduring Understanding
Learning Objective
Essential Knowledge
AP® and Advanced Placement® are registered trademarks of the College Board. The College Board was not involved in the production of this material and does not endorse it. Standards statements above are paraphrased; codes refer back to the official College Board CED, the NCSS C3 Framework, the Common Core State Standards, and other cited frameworks.
AP Practice Questions
- (A) Burgess concentric-zone model.
- (B) Hoyt sector model.
- (C) Galactic city model.
- (D) McGee Southeast Asian city model.
- (E) Griffin-Ford Latin American city model.
Correct: (D). EK PSO-6.D.1 names urban models drawn from Southeast Asia as appropriate for cities such as Jakarta, Manila, and Bangkok. Applying Skill 1.E: McGee fits because Jakarta organizes around an old colonial port (Sunda Kelapa), an ethnic-commercial zone (Glodok), and a government zone (Merdeka) inherited from Dutch colonial administration — features the Western models do not capture.
Scoring: 3 points for three named models; 6 points for one strength and one limitation per model (2 per model, per Skill 1.E); 2 points for best-fit city plus two specific features (e.g., Mexico City + Zocalo CBD + Reforma spine for Griffin-Ford); 2 points for why plurality is needed: different colonial histories, different eras, different transport regimes, different cultural contexts; no single model can describe all of these simultaneously. Total: 13 points.