Sunk-cost fallacy

Spent is gone

A sunk cost is time, money, or effort already spent and unrecoverable. The fallacy is letting it justify spending more.

Escaping a sunk cost means judging a commitment by:

  1. Asking what you would choose today if you were starting fresh.
  1. Counting only future costs against future benefits.
  1. Treating what you already spent as information, not as a reason to continue.

The only question is whether the next dollar earns its return, never what the last one cost.