1. Ullman’s Spatial Interaction Model
AP Human Geography
(for composition book)

2. Travel patterns for purchase of clothing and yard goods
Travel patterns for purchase of clothing and yard goods. A) Canadian rural cash-economy. B) Canadian older Mennonite sect.
Very different travel behaviors show the differences that may exist in the “action spaces” of different cultural groups occupying the same territory.
Getis, Getis, Fellmann

3. Getis, Geits, Fellmann
Chicago Travel Patterns: shows 96% of all trips. What factors influence & create these patterns of interaction?

4. Edward Ullman’s Theory
Spatial Interaction is controlled by three flow-determining factors.
1. Complementarity
2. Transferability
3. Intervening Opportunity

5. Complementarity
For two places to interact, one place must have a supply of an item for which there is an effective demand.
Example: product: Oil - Interaction: US - Middle East
OiL

6. What is Effective Demand?
Desire for the item (demand)
Purchasing Power - $$$
Means to transport the product - rail, road, internet, ship etc.

7. Transferability Refers to mobility of a commodity
Spatial interaction occurs only when acceptable costs of an exchange are met.
Costs include both Time and Money

8. Transferability Function of Three Conditions.
Characteristics and value of product.
The distance measured in time and money.
The ability of the commodity to bear the costs of movement.
Both physical and economic.
If the time and money costs are too great interaction does not occur.
Buyer seeks substitute or goes without product.

9. Intervening Opportunity
Closer opportunities will reduce the the attractiveness of interaction with more distant- even slightly better- alternatives.
Example -ski area in Big Bear. The snow is not as good as Tahoe. But people in Southern Calif. are more likely to ski in Big Bear. B C A

10. Measuring Spatial Interactions
Key Concepts and Theories
-Friction of Distance
-Space time compression

11. Friction of Distance
Distance has a retarding effect on human interactions because there are increasing penalties in time and cost associated with longer distances.