💸 Money

Sunk cost fallacy: why we keep paying for something that stopped working

Continuing to invest money, time or years in something only because you already invested a lot. What it is, why the brain falls for it, and how to get out.

Also called: sunk costs · escalation of commitment

A sunk cost is money, time or effort already spent that you will not get back whatever you do next. The fallacy appears when that past spending becomes the reason to continue: "I have been at this for three years, I am not quitting now."

You stop deciding by looking forward and start deciding by looking backward. What you already spent does not change by spending more.

Why it happens

Quitting hurts more than losing. While you continue, the loss stays theoretical and can be postponed. The moment you stop, it becomes official and you have to say out loud that those years did not work.

There is also an audience. The more people know about the project, the degree or the relationship, the more expensive quitting becomes — you are not just stopping, you are announcing it.

And we confuse persistence with judgement. We are taught that giving up is a character flaw, so enduring feels virtuous even when the project has been dead for months.

What it looks like in real life

The degree you no longer want

Fourth year. You know it is not for you. But it is four years, so you finish, then work two more to "make it worth it", and leave at thirty — with six years spent instead of four.

The business that never took off

You have put in €8,000. Every month with no revenue you add €500 more "so the €8,000 was not wasted". The €8,000 is already gone; this month's €500 is not.

The relationship on autopilot

Five years in. Neither of you has been happy for two. The conversation you avoid is not "do we love each other" — it is "then what was all that time for".

Signs this is happening to you

You justify continuing with facts about the past, not the future.
If you started today, knowing what you know, you would not choose it.
You care more about how quitting looks than about what happens next.
You have set a deadline more than once and moved it.
You already talk about the project in the past tense.

How to avoid it

The newcomer test. Imagine arriving at your own situation today with no history, and being offered the chance to join by putting in only what remains. Would you? If not, the decision is made — the rest is grief.
Set the exit before you start. When you begin something, write down what would make you stop: how much money, how much time, what minimum result. Written while you were still objective.
Separate the project from your identity. A project that fails is not you. While quitting means "I am a failure", you will keep paying to avoid feeling that.
Count what is left, not what is spent. The only number relevant to today's decision is what continuing will cost from here.
Ask someone with nothing at stake. Not family, not partners. Someone who does not look bad if you quit.

Real mistakes from the community

These are not examples we made up. They were written by the people who lived them.

Frequently asked questions

So is quitting always right?

No. The fallacy is not continuing — it is continuing BECAUSE of what you already spent. If the project makes sense looking forward, continue.

How do I tell persistence from sunk cost?

Persistence rests on evidence of progress, however slow. Sunk cost rests on accumulated time. If your only argument is "I have put in so much", it is sunk cost.

Does it affect big companies too?

Especially them. The more a project cost and the more people approved it, the harder it is for anyone to say it should stop.

Can it be avoided entirely?

No, it is automatic. What you can do is build guardrails in advance: written limits, real deadlines, and an outsider who will tell you.

Made this mistake yourself? Writing it down is how someone else avoids it.

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