Sector Model

Definition

The sector model is a theory of urban spatial structure introduced by land economist Homer Hoyt in his 1939 Federal Housing Administration monograph The Structure and Growth of Residential Neighborhoods in American Cities. It holds that a city does not grow as a series of uniform concentric rings but as a set of wedge-shaped sectors radiating outward from the centre along major transport routes. Once a distinctive land use or income group establishes itself in one sector near the core — high-rent housing, say, or industry — the city tends to extend that same use outward along the wedge as it grows, so land-value and residential patterns are organised by direction from the centre as much as by distance from it.[1][2]

Hoyt built the model empirically, from block-by-block residential rent data he compiled for 142 American cities in the FHA's Division of Economics and Statistics. Mapping rent gradients, he found that high-value residential areas clustered and migrated within radial wedges rather than forming an even ring at a fixed distance — the observation the sector model generalises.[1]

Relation to Earlier Models

The sector model is usually presented as a refinement of Ernest Burgess's concentric-zone model (1925), which pictured the city as a bull's-eye of successive rings (central business district, transition zone, working-class housing, better residences, commuter belt) expanding uniformly outward. Hoyt's correction was directional: growth follows lines of least resistance — rail lines, arterial roads, waterfronts, high ground — so a single land use pushes out along a sector while other uses dominate other sectors at the same radius.[2] Both models descend from the same underlying insight that organises this wiki's land corpus — that urban land rent is a function of location, the spatial rent theory Johann Heinrich von Thünen founded with his concentric rings a century earlier. The sector model is one empirical account of how that location rent distributes itself across a real, transport-shaped city.

Connection to Land-Value Assessment

Because the sector model is a claim about the spatial pattern of land values — that similar land uses and rent levels line up along directional wedges — it bears directly on how assessors think about mapping and estimating land value across a jurisdiction. The modern statistical successor is mass appraisal: computer-assisted systems model sale price as a function of location and parcel attributes, and the sector model's core premise — that location, and specifically which direction from the centre, dominates the value of otherwise-similar parcels — is exactly the regularity such site-value estimation exploits when isolating the land component for a land value tax. The sector model predates CAMA by decades but describes the same structure those methods now quantify.

The Chicago Data Behind It

The sector model grew out of the same research programme as Hoyt's better-known 1933 University of Chicago dissertation, One Hundred Years of Land Values in Chicago, which reconstructed a century of Chicago land values and is the founding empirical source behind the Georgist 18-year land cycle. That book supplied the long-run, block-level land-value mapping technique Hoyt then applied across many cities at the FHA; the sector model is the cross-city generalisation of the intra-city land-value patterns he first documented in Chicago.[3]

Nuances and Limits

• Not a Georgist theory, and no LVT content. Hoyt was not a Georgist and the sector model contains no argument for land value taxation. Its relevance here is descriptive: it is a widely cited account of the spatial structure of urban land value, the thing an LVT taxes.
• A model of tendencies, later contested. Like the concentric-zone model it refined, the sector model is a mid-century idealisation. Later urban geography (the Harris–Ullman multiple-nuclei model of 1945, and modern agglomeration economics) treats real cities as having many centres and more complex value surfaces than any single wedge or ring diagram captures.
• Documented redlining legacy. The sector model's neighbourhood-succession logic was carried directly into FHA mortgage-underwriting doctrine. Hoyt's work — including an explicit ranking of "races and nationalities with respect to their beneficial effect upon land values" that first appeared in the 1933 Chicago dissertation (pp. 314–316) — fed the appraisal theories behind the FHA's discriminatory underwriting and Residential Security Maps (redlining). This history is documented in full on the Homer Hoyt page and should not be elided when citing the model.

See Also

• Homer Hoyt — the model's author
• One Hundred Years of Land Values in Chicago — the Chicago land-value study behind it
• Mass Appraisal Methods — the modern assessment successor
• Johann Heinrich von Thünen — location theory, the spatial-rent foundation
• Site Value · Land Value Tax

Sources

1. Homer Hoyt (Federal Housing Administration), The Structure and Growth of Residential Neighborhoods in American Cities, Washington, D.C.: U.S. Govt. Printing Office, 1939 (202 pp.; U.S. Government document, public domain). Full text (Internet Archive) — the primary source: the sector model and the 142-city residential rent data behind it (A-claim; catalogue record confirms authorship, date, and the FHA Division of Economics and Statistics attribution).
2. Robert Beauregard, "More Than Sector Theory: Homer Hoyt's Contributions to Planning Knowledge," Journal of Planning History 6(3), 2007. Sage Journals — used for the sector model's content, its refinement of Burgess's concentric-zone model, and its standing in twentieth-century planning scholarship (A-claim, abstract-level; full text not independently read).
3. This wiki's research summary of One Hundred Years of Land Values in Chicago and Homer Hoyt biography — used for the continuity between the 1933 Chicago study and the 1939 sector-model work, Hoyt's FHA career (chief/principal land economist, 1934–1940), and the documented redlining legacy.