Cognitive bias
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Part of:Decisions without regret →
All fallacies and biasesCognitive biases list
Sunk-cost thinking lets a past loss decide a future choice. Money or time already spent is gone whether you continue or stop. The live question is which option is better from now on.
Sunk cost is filed here as a bias. If you cannot point to that move in the remark in front of you, you do not yet have this bias. Disliking the conclusion is not enough, and a true premise does not repair a broken step.
This page adds no new definition and no statistic. The three scenes below only move the library’s example into a meeting, a news sentence, and a social feed. None of them is a reported case, and none of them carries a number.
The library’s example is the anchor, quoted so the later scenes cannot drift: “You keep attending a class you dislike because you have paid the fee, even though a different class would serve you better and the fee will not be refunded either way.” The three that follow change the room and keep the step.
Picture that example in a meeting, aimed at someone who has to answer before the next item. If the room cannot give the reply on the card, it has not answered the point. It has used Sunk cost. No survey of offices is claimed. The test is whether the step matches the card.
The same step can sit in a speech or a headline, where the pause is shorter and the audience is larger. Imagine the stored example said into a microphone and left unpacked. This is not a claim about a particular broadcast or a particular paper. The correction is still the reply on the card, not a different theory of the press.
Imagine the example as a caption. Agreement is not evidence the step was valid, and outrage is not evidence a different bias was in play. Match the step to the definition before you name it.
Write the past payment on a line you cannot get back. Then compare only the future costs and benefits of staying and of switching.
“That is Sunk cost” is not yet an answer. Name the step, then ask the question the card tells you to ask. If the remark survives, drop the label. If it fails, you still owe a reason for what you think instead. The reply does not hand you a new conclusion.
Sunk cost is easy to shout in place of a neighbour. The nearest card people mix this up with is Status-quo bias. Use the comparison linked under this section when you are unsure which name fits. The comparison quotes the cards. It does not invent a third definition.
Write down the sentence you think is the mistake. If it matches one definition, use that name. If it matches neither, do not force a label. If it matches both, answer the two steps separately.
The hotel is grim and the money will not come back, but you stay the week because it is already spent. Which bias is this?
The options and the explanation open in the quiz. Scoring stays on this device. There is no pass mark on this card.
Sunk-cost thinking lets a past loss decide a future choice. Money or time already spent is gone whether you continue or stop. The live question is which option is better from now on.
You keep attending a class you dislike because you have paid the fee, even though a different class would serve you better and the fee will not be refunded either way.
Write the past payment on a line you cannot get back. Then compare only the future costs and benefits of staying and of switching.