Christopher Olivola
Christopher Y. Olivola is a behavioural scientist at Carnegie Mellon University and the author of the 2018 paper in Psychological Science reporting the interpersonal sunk-cost effect: people change their own choices in response to costs that somebody else paid. Across eight experiments with just over six thousand participants, the effect held regardless of how close they felt to the person who had paid, and regardless of whether anybody could see them honouring it.
Who they are
The reason this result matters more than another demonstration is that it decides between two rival explanations rather than adding to the pile.
The two accounts are self-justification, the idea that people persist in order to defend a decision they made themselves, and waste aversion, the idea that people are following a learned rule against letting things go to waste. Honouring a stranger's wasted money, unobserved, is very hard to explain as defending your own record. It looks like a norm.
Key papers
Olivola, C. Y. (2018). "The interpersonal sunk-cost effect", Psychological Science. Eight experiments, 6,076 participants. The effect was not moderated by social closeness and not moderated by whether the behaviour could be observed.
Key ideas
The strongest single result for the waste-aversion account, which is why it is the evidence carried at Waste Aversion.
It argues against self-justification as a complete account, though not against it as the better explanation for cases where somebody did choose the failing course themselves. That is carried at Escalation of Commitment, and this site uses both accounts, each where its evidence is.
The two design features are what make the argument work. If the effect had faded with social distance, or disappeared when nobody was watching, a self-presentation story would have survived. Neither happened.
The reading is only as good as the source. This site has read the abstract and reported design rather than the full text, and the finding is presented on that basis.
Concepts on this site
Waste Aversion, the account his result supports most strongly
Sunk Cost Fallacy, the effect he extended past the self
Escalation of Commitment, the account his result argues against
Sources
- Olivola, C. Y. (2018). Psychological Science. Eight experiments, 6,076 participants. Abstract and reported design only.
- Vault record, 2026-09-11, for Why You Finish the Series You Stopped Enjoying.