Sunk cost fallacy: Throwing good money after bad

In economics, a sunk cost is any cost that has already been paid and cannot be recovered. The sunk cost fallacy is a mistake in reasoning in which the sunk costs of an activity - instead of the future costs and benefits - are considered when deciding whether to continue the activity.  The sunk cost fallacy makes it more likely that a person or an organization continues with an activity in which they have already invested money, time, or effort, even if they would not start the activity had they not already invested in it. The greater the size of the sunk investment, the more people tend to invest further, even when the return on added investment appears not to be worthwhile. This trap is sometimes described as "throwing good money after bad," because the resources and effort are already lost, no matter what you do now.