Sunk cost refers to whatever resources have already been spent. Where it becomes a fallacy is thinking along the lines of But I’ve already invested this much mo

Sunk cost refers to whatever resources have already been spent. Where it becomes a fallacy is thinking along the lines of But I’ve already invested this much money or You know, I’ve been working on it for all these years, so I CAN’T quit now. What we’ve paid into it is gone — a sunk cost — and what matters is how much additional investment from where we stand now will be required to complete the goal and whether that cost will be worth it when considered against other opportunities for the same time, money, and attention. In some sense, we start at even every day.