Individuals free to move between resource patches distribute themselves so that returns per individual equalise, so the best patch is not the best place to be.
Fretwell and Lucas's 1969 model predicts that if everyone can see and reach every patch, the crowding in the rich patch will erode its advantage until no move improves anyone's position. Fish, birds and human shoppers approximate it. The counter-intuitive consequence is that observed equal returns are evidence of unequal resources, not of equal ones.
In practice
- Two supermarket queues of different length move at the same speed, which is why switching rarely helps.
- A profession that pays well attracts entrants until the return matches the alternatives, and then looks ordinary.
- Further reading
- Wikipedia
- Subject
- Sociology & Culture
- Essay
- How societies hold together, sort people, and change