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Sunk-cost fallacy

Continuing a choice because of unrecoverable past investment instead of its future value.

Published 04 August 2026Updated 04 August 2026

The sunk-cost fallacy lets money, time, effort, or emotion already spent influence a decision that should depend on future costs and benefits. Ask what you would choose now if you had not made the earlier investment.

Sources

Prospect Theory: An Analysis of Decision under Risk

Econometrica / 1979 / Paper

Reference for loss aversion and framing effects.