Sunk Cost Fallacy
The tendency to continue a course of action because of past investment in it (time, money, emotion, effort) rather than on the basis of current expected value. In Bible study, this manifests as refusing to revise theological positions one has taught, written about, or built a ministry around, even when presented with compelling contrary evidence.
Source: Richard Thaler (1980) – Public Domain
Also known as: Concorde fallacy, sunk cost bias, escalation of commitment
The sunk cost fallacy is the cognitive and motivational error of continuing to invest in or defend a course of action because of the resources already committed to it — the 'sunk costs' — rather than on the basis of the future value that investment is expected to produce. Since sunk costs cannot be recovered regardless of future decisions, rational decision theory holds that they should not influence current choices.
The sunk cost fallacy is well-documented across economic, behavioral, and social psychology research. It explains why people finish books they are not enjoying, stay in unsatisfying relationships, continue military campaigns without strategic justification, and maintain business ventures that have ceased to be profitable — all to avoid the psychological discomfort of acknowledging that a prior investment was wasted. The fallacy is cognitively powered by loss aversion (the pain of loss is felt more acutely than equivalent gain), by identity investment (the prior commitment has become part of one's self-concept), and by social accountability (others know about the commitment and will observe if it is abandoned).
In theological and biblical interpretation contexts, the sunk cost fallacy operates with particular force because the prior investments are often not merely intellectual but pastoral, social, and vocational. A pastor who has preached the same interpretation of Romans 9 for twenty years has invested sermon preparation, relational capital, denominational credibility, and congregational trust in that view. A theologian who has published a monograph defending a particular reading of Daniel has invested academic reputation. A Sunday school teacher who has taught the same view for a decade has invested time, authority, and relationships. For any of these figures, revising their interpretation means acknowledging — at least implicitly — that the prior investment was at least partially mistaken.
The result is that people who have invested most heavily in a position are often the least capable of evaluating it objectively. The very people with the deepest knowledge of a subject have the most sunk costs in their existing positions. This is one reason why genuine intellectual paradigm shifts in any field, including biblical scholarship, are often led by younger or newer scholars who have invested less in the old paradigm.
- 1You refuse to revise an interpretation primarily because you have taught it for many years, written about it, or built ministry programming around it
- 2When challenged, your first thought is 'but I've already told so many people this' rather than 'is the challenge actually correct?'
- 3You feel that changing your view on a significant interpretive question would be an admission of past failure rather than an exercise of intellectual virtue
- 4You frame intellectual revision in terms of what it would cost you personally (reputation, credibility, relationships) rather than in terms of what the evidence actually warrants
- 5You find it significantly easier to acknowledge that a historical theologian's view was wrong than to acknowledge the same of your own past writing or teaching
Paul's statement in Philippians 3:8 is perhaps the most striking biblical engagement with what we would call the sunk cost fallacy. He describes his prior investment in Jewish heritage, Pharisaic training, and religious credentials — everything he once counted as gain — as 'loss' and 'rubbish' compared to knowing Christ. Paul literally inverts the sunk cost logic: the prior investment, which would normally argue for preservation and continuation, is explicitly devalued in light of a more accurate understanding. Galatians 1:14 provides the biographical background: Paul had 'advanced in Judaism beyond many of my peers,' investing enormous personal capital in his former position. The willingness to abandon that investment entirely — in response to genuine revelation rather than mere persuasion — stands as a canonical model of refusing to be held captive by sunk costs.
Inventory your prior investment
Ask: How much have I invested in this interpretive position — in terms of time, public teaching, published writing, relational capital, or identity? How much would it cost to revise it?
Name the costs honestly: 'I have taught this for ten years.' 'I wrote a book chapter defending this view.' 'My close mentors hold this position and I would have to explain a revision to them.' Making the sunk costs explicit allows you to ask whether they are influencing your evaluation of the evidence.
Separate the evidence question from the cost question
Ask: Setting aside what revision would cost me, what does the evidence actually indicate about whether my view needs updating?
Evaluate the counterevidence as if you had no prior investment in the question at all. Ask: 'If I were studying this topic for the first time and encountered this evidence, what would I conclude?' The answer to the evidence question and the answer to the cost question should be kept strictly separate.
Reframe revision as virtue
Ask: Can I think of intellectual revision not as admission of failure but as exercise of the virtue of honesty and continued learning?
Intellectual humility is itself a biblical virtue (Proverbs 1:5, Romans 12:3). A teacher or scholar who visibly updates their view in response to evidence models exactly the kind of ongoing engagement with truth that Christian intellectual life should embody. The sunk cost fallacy reframes this virtue as a vice (embarrassment, inconsistency); recovering the virtue requires consciously reframing it.
Consider the cost of not revising
Ask: What is the cost of maintaining a position I have reason to doubt — to my own intellectual integrity, to those I teach, to my relationship with the truth?
The sunk cost fallacy focuses on the cost of revision. But there are also costs to non-revision: ongoing intellectual dishonesty, potentially misleading those who trust your teaching, foreclosing genuine engagement with the text, and modeling the opposite of the Berean virtue. Weighing these costs against the sunk costs of revision rebalances the decision.
Identify the minimum honest revision
Ask: Even if full revision is not warranted, is some honest qualification, nuancing, or acknowledgment of uncertainty the right response to the evidence I have encountered?
Full position reversal is often not required — and sometimes genuinely not warranted. But the evidence may warrant a qualification: 'I have always taught X, but I now recognize that Y is a serious scholarly alternative that I cannot dismiss.' The capacity for micro-revision in response to evidence is the minimum level at which intellectual honesty operates, and the sunk cost fallacy often prevents even this.