A bad purchase can make you want to spend even more.

Why yesterday’s investment can distort today’s choice

Imagine a business owner deciding whether to keep a struggling product alive. The next production run will cost money, and the likely sales no longer justify it. Yet the owner remembers the months spent developing the product and the budget already used. Those past costs cannot be recovered whether the project continues or stops. The relevant question is what each option is likely to cost or return from this point forward.

When earlier spending weighs heavily in the decision, psychologists call the pattern the sunk cost effect. A sunk cost is a resource already spent that cannot be retrieved. It may be money, time, effort, or an opportunity passed up along the way. Because it is gone either way, it should not by itself make further investment worthwhile.

How commitment becomes a reason to continue

Stopping can feel like admitting that earlier choices were mistakes. That discomfort encourages people to reinterpret weak results as temporary setbacks, search for reasons the payoff may still arrive, or make one more investment to justify the last one. The more publicly someone defended a choice, the harder it can be to abandon it without feeling that they are also abandoning their own judgment or competence.

This is not simply a failure to do arithmetic. The decision is tangled up with regret and identity: continuing offers the hope that the past will eventually make sense, while stopping makes the loss unmistakable. But the hope of recovering earlier costs does not change the odds of future success.

A forward-looking test

A useful reset is to ask: If I had not invested anything yet, would I choose to begin this now, given what I know today? That question does not mean past effort is irrelevant in every way; it may have produced useful skills, information, or relationships. Those benefits can matter if they improve the prospects of the next step. The unrecoverable cost itself cannot.

For the product owner, the practical choice is not “save the money already spent” versus “waste it.” That money is already spent. The choice is whether the next production run is a better use of resources than the alternatives—and whether ending the project now prevents a disappointing decision from becoming an even larger one.