1. Rank-Size Rule

2. Definition:
Relatively developed societies produce a pattern in the size of their cities according to a mathematical formula.

3. “Ideal” line

4. How Well does the USA fit?
New York City, NY m
Los Angeles, CA m
Chicago, IL m
Houston, TX m
Philadelphia, PA m
Phoenix , AZ m
San Antonio, TX m
San Diego, CA m
Dallas, TX m
San Jose, CA ,000

5. U.S. Line

6. How does the U.S. Compare?

7. PRIMATE CITIES
In less developed countries/regions the largest city is overly large. The pattern of settlements is such that the largest settlement has more than twice as many people as the second largest settlement.

9. Mexico México City 8.6 m Guadalajara 1.6 m France Paris 9.6 m
Country
Primate City
Population
Next largest city
Mexico
México City
8.6 m
Guadalajara
1.6 m
France
Paris
9.6 m
Marseille
1.3 m
United Kingdom
London
7 m
Birmingham
1 m
Thailand
Bangkok
7.5 m
Nanthabury
481,000
Denmark
Copenhagen
Århus
200,000
Romania
Bucharest
1.9 m
Iasi
315,000

19. Why do we care? Interesting math!
Countries that have good rank-size distribution improve the quality of life of their citizens. A regular hierarchy (USA) indicates that a society is wealthy enough to provide services for its people.
Absence of rank-size means people may struggle to access large urban settlements, thus high level services like hospitals.