Planning Fallacy

In a series of experiments on predicting task completion times, researchers found that people often make plans based on hopeful expectations, rather than considering past experiences.


People tend to be overly optimistic when planning future tasks, often overlooking the actual time and resources needed.

See the full study here :

Buehler, R., Griffin, D., & Ross, M. (1994). Exploring the” planning fallacy”: Why people underestimate their task completion times. Journal of personality and social psychology, 67(3), 366.

Want to know more about biases?

Third Person Effect

Spotlight Effect

Cooling Off Period

Decision Fatigue