Transcript Distribution of Consumer Services

Central Place Theory
“Models are not real, but help us
understand reality”
Central Place Theory
• Central Place: market center for
the exchange of goods and
services by people attracted
from the surrounding area
• Theory explains how services
are distributed and why a
regular pattern of settlements
exists
• German geographer Walter
Christaller (1930)
The Cumberland Valley of
Pennsylvania is a portion
of the Great Valley of the
Appalachians. Broad
valley floor, agricultural,
settled in the early-to-mid
1700s
Note the regularity of
spacing between urban
centers -- towns. Local
lore has it that the
distances between towns
evolved because it was the
distance someone could
travel in a day.
“If . . . “
• Isotropic Surface
– “featureless plain” with no barriers to movement
• Even Population Distribution
– similar in purchasing power and behavior
• Homo Economicus
– “economic man” with purely economic motives
• Integrity of the Law of Supply and Demand
– customers needed for a business to stay open
“Then . . . “
• There will be a regular spatial order in the number of
central places of different population sizes.
– Few large places
– Many small places
• There will be a regular spatial order in the spacing of
central places of different population sizes.
– Large places relatively farther apart
– Small places relatively closer together
Central Place Functions
Categories of like services found in a
central place
•
•
•
•
•
•
Grocery Stores
Gas Stations
Jewelry Stores
Book Stores
Hair Stylists
Auto Dealerships
•
•
•
•
•
•
Houses of Worship
Schools
Doctors
Dentists
Museums
Concert Halls
Would you travel farther to buy a new car or the
week’s groceries?
To buy a new car
Would you travel farther to see your family
physician or a heart specialist?
To see a heart specialist
Would you travel farther to go to elementary
school or to go to high school?
To go to high school
A Hierarchy of
Educational
Services
City:
College
Town:
High School
Village:
Elementary
School
Hamlet:
No Schools
Stock Exchange
Sports Stadium
Regional Shopping Mall
Major Department Store
Income Tax Service
Convenience Store
Gas Station
How big is the trade area of a
service center?
It depends on . . .
- How far a consumer is willing to
travel for the service
- How many customers a service
needs
Each central place function has a:
• Threshold: the
minimum number of
people needed to
support a central place
function
• With fewer customers a
store cannot afford to
stay in business.
• Range: the maximum
distance beyond which
a person will not travel
to purchase a good or
service
• Beyond a certain
distance people cannot
afford the travel costs.
Optimal Location
(for Pizza Shop)
Fig. 12-6: The optimal location for a pizza delivery shop with seven potential customers in
a linear settlement (top) and with 99 families in apartment buildings (bottom).
Supermarket and Convenience Store
Market Areas
Fig. 12-8: Market area, range, and threshold for Kroger supermarkets (left) and UDF
convenience stores in Dayton, Ohio. Supermarkets have much larger
areas and ranges than convenience stores.
Best Location in a Linear Settlement
Rank Size Rule
George Zipf – 1949
• The country’s nth
•
largest settlement is 1/n
the population of the
•
largest settlement
2nd largest city is ½ the
largest
4th largest city is ¼ the
size of the largest
Rank-Size Rule: United States
City
Population
New York City
8,391,881
Los Angeles
3,831,868
Chicago
2,851,268
Houston
2,257,926
Phoenix
1,593,659
Philadelphia
1,547,297
San Antonio
1,373,668
San Diego
1,306, 300
Rank-Size Distribution of Cities
Fig. 12-9: Cities in the U.S. closely follow the rank-size distribution, as indicated by the
almost straight line on this log scale. In Romania, there are few
settlements in two size ranges.
Primate City Rule
• The largest settlement
has more than twice as
many people as the
second-ranking
settlement.
• Primate City=largest city
• Denmark
– Copenhagen 1 million
– Arhus 200,000
• United Kingdom
– London 8 million
– Birmingham 2 million
• Thailand
– Bangkok 1.5 million
– Nonthaburi 250,000