1. Gravity model
by Jalon Kimes

3. The gravity model was created to predict migration between cities.
The gravity model resembles Newton’s theory of gravitational pull.

4. What is the gravity model?
The Gravity model predicts that the optimal location of a service is directly related to the number of people in the area.

5. How does the gravity model work?
The Gravity Model takes into account the the size of the population in two places and their distance.
Places closer together have greater attraction and larger places attract people, commodities, and ideas. The gravity model incorporates these features.

6. How does the gravity model work? cont.
In order to determine the bond between two places you have to multiply the population of one city by another city and divide that answer by the distance between the two places squared.

7. Example The population of Boston is 645,966.
The population of Atlanta is 447,841.
The distance between them is 1,084 miles.
645,966 x 447,841=289,290,059,406

8. Next you divide 289290059406 by 1,084 miles squared
divided by 1,175,056 =246,193
124,193 is the strength of the bond between Atlanta and Boston