What it sounds like
- I have spent three years on this bad project, so I have to keep going.
- "We have spent six months on this campaign, so we have to launch it." Or we could stop converting effort into a bonfire.
Logical fallacy
Sunk Cost Fallacy
Continuing something because you have already invested time, money, or effort.
Classic tell: I have spent three years on this bad project, so I have to keep going.
Back to the guideFurther explanation
What is happening underneath?
Continuing something because you have already invested time, money, or effort.
Past investment is used to justify future investment, even when the future case is weak. The money/time is gone; the next choice still matters.
How to tell
- The reason to continue is mainly what has already been spent, not what is likely to happen next.
Why people use it
- Quitting feels like admitting loss, so people buy more loss to avoid feeling foolish.
How to combat it
- Say: "If we were deciding today with no prior investment, would we choose this?"
Manipulation watch
How this gets used on people.
- Subscriptions, memberships, and culty programs exploit sunk cost: you have come this far, so leaving now would waste the journey.