Billion-Dollar Sunk Costs

The sunk cost fallacy operates at every scale, from movie tickets to megaprojects:

• The Concorde jet — Britain and France kept funding it for decades despite knowing it would never be profitable; the project later became shorthand for the phenomenon, the "Concorde fallacy"
• Failed startups — founders pour savings into dying businesses because they have "come too far to quit"
• Bad relationships — people stay in unhappy partnerships because of the years already invested
• War escalation — governments justify more fighting by honoring soldiers already lost.