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.
Used in the Books
This term appears in 2 chapters:
"J. (2001). Ecological traps in changing environments: Ecological and evolutionary consequences of a behaviourally mediated Allee effect. Evolutionary Ecology Research, 3(5), 537-551."
"From billions to zero in fifty years. Not from lack of individuals, but from lack of critical mass. This is what biologists call the Allee effect. I call it The Allee Trap - when you die from isolation while still numbering in the millions. The Allee Trap kills organizations too: network-e..."
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.