Sunk-Cost Fallacy

The sunk-cost fallacy is the tendency to continue investing in a project or decision based on past investments, rather than making a new decision based on current and future value.

To prevent it, it's important to make decisions based on current and future value, rather than past investments. Ask yourself: "If I were starting today, would I still choose this?"

The costs are already paid; only future costs and benefits should guide the decision. Cutting losses frees resources for higher-leverage work.