A feedback loop is a closed chain of causal connections from a stock, through a set of decisions or rules or physical laws or actions that are dependent on the level of the stock, and back again through a flow to change the stock. If you see a behavior that persists over time, there is likely a mechanism creating that consistent behavior. That mechanism operates through a feedback loop. It is the consistent behavior pattern over a long period of time that is the first hint of the existence of a feedback loop.
Balancing feedback loops are equilibrating or goal-seeking structures in systems and are both sources of stability and sources of resistance to change.
The second kind of feedback loop is amplifying, reinforcing, self-multiplying, snowballingâa vicious or virtuous circle that can cause healthy growth or runaway destruction1.
1. Meadows, D. H. Thinking in Systems: A Primer. (Chelsea Green Publishing, White River Junction, Vt, 2008).