Irrational Escalation as Rational Strategy: Reframing Decision Theory

The sunk cost fallacy is not a bug in human decision-making—it's a feature that reveals something fundamental about how we navigate commitment and identity.

For decades, behavioural economics has treated sunk cost reasoning as a cognitive error. Kahneman and Tversky's framing effects showed us that rational actors should ignore past investments when evaluating future choices. Yet this framework misses a critical dimension: the decision-maker is not a disembodied calculator. They are embedded in relationships, reputations, and narratives about themselves. When someone continues investing in a failing project, they are not simply miscalculating. They are managing something far more complex—the coherence of their identity and the signals they send to others about their reliability.

Consider a customer who has spent five years with a brand, despite accumulating friction. The rational model predicts they should leave the moment a competitor offers better value. But the actual decision involves something the spreadsheet cannot capture: the cost of admitting error. Walking away means conceding that years of choice were wrong. It means rewriting the story they tell themselves about their own judgment. The sunk cost is not really about money. It is about the self.

This reframing changes what we should measure. If we only track defection rates and price sensitivity, we miss the deeper mechanism: customers who have invested time and identity in a brand experience genuine psychological resistance to leaving, independent of rational utility calculations. This is not irrational. It is a different kind of rationality—one that accounts for the social and psychological costs of inconsistency.

The implications for strategy are substantial. Brands that understand this dynamic can design experiences that deepen identity investment without relying on artificial lock-in. Every interaction becomes an opportunity to reinforce the customer's sense of themselves as someone who made a good choice. This is not manipulation. It is alignment with how humans actually make decisions.

But there is a darker application worth examining. The same mechanism that keeps customers loyal can trap them in genuinely bad situations. Escalating commitment to a failing strategy, a toxic relationship, or a misaligned career path follows identical psychological logic. The person is not irrational; they are protecting their sense of self-consistency. The problem is that this protection mechanism can override genuine signals that change is necessary.

The distinction matters because it suggests different interventions. If sunk cost reasoning is simply a calculation error, the solution is education—teach people to ignore the past. But if it is identity protection, education alone fails. People need permission to change their minds. They need narratives that reframe departure not as failure but as growth. They need to see that consistency can mean evolving, not repeating.

This is where the current decision theory framework becomes limiting. Kahneman's work brilliantly exposed systematic biases, but it was built on a model of the decision-maker as fundamentally solitary. Real decisions happen in social contexts where reputation, narrative, and identity are currencies as real as money. A customer's choice to stay with a brand is not separable from their choice to be the kind of person who is loyal, who doesn't jump around, who gives things time to work.

The practical insight: if you want to understand why people make the choices they do—and crucially, how to influence those choices—you must account for the identity dimension. This is not about exploiting cognitive biases. It is about recognizing that the human decision-maker is simultaneously rational and narrative-driven, calculating and identity-protective.

The brands and organizations that will thrive are those that stop treating sunk cost reasoning as an error to overcome and start treating it as a feature to align with. Make it easy for customers to see themselves as people who made good choices. Make staying coherent with their identity. Make leaving require not just finding something better, but becoming someone different.

That is not irrational escalation. That is strategy built on how humans actually decide.