Mental model · Deciding

Sunk cost

Sunk cost: What has already been spent cannot be recovered by continuing, so it should not enter the decision.

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What has already been spent cannot be recovered by continuing, so it should not enter the decision.

Try it now

Find something you are continuing partly because of what you have already put in. Write the amount.

What to do with the answer

Ask: if I arrived today with no history here, would I start this? Decide from there.

Where it misleads

Past investment sometimes IS relevant — as evidence about how hard the thing is, or as a commitment others rely on. Distinguish those from pure sunk cost.