Population Dynamics
Allee Effect
A phenomenon where individual fitness or population growth rate increases with population density, at least at low densities. The opposite of typical density-dependent effects where crowding reduces fitness.
Biological Context
At low population densities, it becomes harder to find mates, defend against predators collectively, or maintain genetic diversity. This creates a threshold below which populations spiral toward extinction. The Allee effect explains why small populations face disproportionate extinction risk.
Business Application
Business Allee effects: network products need critical mass to be valuable, marketplaces need minimum liquidity, and teams need enough members to be effective. Below threshold, value collapses.