What is Behavior cost?
Behavior cost is the total burden a person must bear to perform a behavior, including time, effort, money, cognitive load, social risk, and emotional discomfort. It is the behavioral economics equivalent of ‘price’ applied to any action, not just purchases.
How it works
Behavior cost explains why people fail to do things they want to do: the cost is higher than the perceived benefit at the moment of action. Critically, behavior cost is subjective and context-dependent. Filling out a 10-minute form feels trivial when motivated and overwhelming when tired. The same action has different costs at different times. Reducing behavior cost is often more effective than increasing motivation because it works even when motivation is low.
Applied example
Signing up for a gym that is 20 minutes away has a higher behavior cost than one that is 5 minutes away, even if the farther gym is cheaper and better equipped. The daily commute cost accumulates and eventually outweighs the initial motivation.
Why it matters
Behavior cost is the primary lever in behavioral design: most behavior change failures are not motivation failures but cost failures, where the cumulative friction of performing the behavior exceeds the motivation to do it.
