Retail gravitation follows an inverse square relationship with distance.
Reilly's 1931 formulation. It survives in retail siting models and is the ancestor of the gravity models used for migration and trade flows.
In practice
- A town of 60,000 draws shoppers from villages twice as far out as a town of 15,000 does, and the boundary between them sits nearer the smaller.
- A supermarket's catchment is not a circle but a shape determined by where the next supermarket is, which is what the inverse-square form captures.
- Subject
- Economics & Incentives
- Essay
- The regularities money obeys