Sunk Cost Drift: Why You Can't Kill That Failing Project

You've been building a feature for six months. Twenty-two people use it. You know, somewhere beneath the optimism, that it's not working. But you've already spent $80,000 and 400 engineering hours on it. Walking away feels like admitting failure. This is Sunk Cost Drift.

Sunk Cost Drift is the cognitive pattern that convinces you to keep investing in a failing trajectory because of what you've already invested. The past is gone — but it's steering your future decisions.

The Trap

The trap is subtle. It doesn't feel like irrationality — it feels like commitment. You tell yourself:\n\n- 'We're so close to a breakthrough'\n- 'We can't waste everything we've built'\n- 'The next feature will change everything'\n\nThese are the mantras of Sunk Cost Drift. The pattern feeds on the gap between the effort you've invested and the results you've achieved. Closing that gap feels urgent — even when the rational move is to walk away.

The Antidote

The simplest antidote to Sunk Cost Drift is to ask one question: **If I inherited this project today with zero emotional attachment, would I start it?**\n\nIf the answer is no, you know what to do. The past investment is irrelevant. The only thing that matters is the expected value of the future — and that doesn't change based on what you've already spent.