Loss Aversion
Edited by Paweł Raja, PhD · Published · Updated
Definition
Loss Aversion is the psychological tendency to feel the pain of a loss more strongly than the pleasure of an equivalent gain — by most estimates roughly twice as strongly.
Why it happens: the psychology of loss aversion
Loss aversion is a core part of Kahneman and Tversky's prospect theory (1979). People judge outcomes as changes from a reference point rather than as final wealth, and the value function is steeper for losses than for gains. Losing $100 hurts more than winning $100 pleases.
The size of the asymmetry is usually expressed as a loss-aversion coefficient (λ). Tversky and Kahneman (1992) estimated a median of about 2.25. A 2024 meta-analysis of several hundred estimates by Brown, Imai, Vieider and Camerer puts the average close to 2, with wide variation across people, tasks and elicitation methods.
The endowment effect is loss aversion applied to things you own. In Kahneman, Knetsch and Thaler's (1990) mug experiments, owners asked roughly twice as much to sell a mug as non-owners were willing to pay for it. Giving the mug up felt like a loss.
Loss aversion is not beyond dispute. Gal and Rucker (2018) argue that many effects credited to it are better explained by inertia and a preference for the status quo, and that for small stakes losses and gains are often weighted similarly. The effect is strongest for meaningful amounts and when a clear reference point exists.
Loss Aversion examples
People are much more motivated to avoid a $50 surcharge or penalty than they are to obtain a $50 discount or reward.
- Investors often hold a losing stock far too long, unwilling to 'lock in' a loss, while selling winners too early.
- A '30-day money-back guarantee' works partly because once people own something, giving it up feels like a loss.
How to design for it (nudge strategy)
Reframe promotional incentives from 'Gain $100 by signing up' to 'Stop losing $100 every month you wait'. Use trial periods where users 'own' the service before purchasing.
Ethical use: design for choices people would endorse on reflection — a nudge, not sludge. Be transparent and keep opting out easy.
The evidence (1)
- Overcoming Saving Inertia with Future Commitments
Finance · Average Retirement Saving Rate: 3.5% → 13.6% (+10.1 pts) · n = 3 companies, 1,200 employees
Key studies
Introduced reference-dependent preferences in which losses loom larger than gains.
Kahneman, D., & Tversky, A. (1979). Prospect theory: An analysis of decision under risk. Econometrica, 47(2), 263–291. DOI →
Estimated a median loss-aversion coefficient of about 2.25.
Tversky, A., & Kahneman, D. (1992). Advances in prospect theory: Cumulative representation of uncertainty. Journal of Risk and Uncertainty, 5(4), 297–323. DOI →
Mug owners demanded about twice what buyers would pay — the endowment effect.
Kahneman, D., Knetsch, J. L., & Thaler, R. H. (1990). Experimental tests of the endowment effect and the Coase theorem. Journal of Political Economy, 98(6), 1325–1348. DOI →
Professional golfers putted more accurately for par (avoiding a 'loss') than for birdie, even among top players.
Pope, D. G., & Schweitzer, M. E. (2011). Is Tiger Woods loss averse? Persistent bias in the face of experience, competition, and high stakes. American Economic Review, 101(1), 129–157. DOI →
Pooled estimates put the average loss-aversion coefficient close to 2, with substantial heterogeneity.
Brown, A. L., Imai, T., Vieider, F. M., & Camerer, C. F. (2024). Meta-analysis of empirical estimates of loss aversion. Journal of Economic Literature, 62(2), 485–516. DOI →
A critique arguing that many 'loss aversion' results reflect inertia or status-quo preference instead.
Gal, D., & Rucker, D. D. (2018). The loss of loss aversion: Will it loom larger than its gain? Journal of Consumer Psychology, 28(3), 497–516. DOI →
Key research
- Prospect Theory: An Analysis of Decision under RiskDaniel Kahneman, Amos Tversky · Econometrica (1979)
Related biases
Loss Aversion: frequently asked questions
What is loss aversion in simple terms?
Loss aversion means losing something feels worse than gaining the same thing feels good. Most studies find losses weigh roughly twice as much as equivalent gains.
What is an example of loss aversion?
Investors hold losing stocks too long to avoid 'locking in' a loss; shoppers respond more to avoiding a $5 surcharge than to earning a $5 discount; golfers putt more carefully to save par than to make birdie.
What is the difference between loss aversion and risk aversion?
Risk aversion is preferring a certain outcome to a gamble with the same expected value. Loss aversion is weighting losses more than gains relative to a reference point. Loss aversion can even make people risk-seeking when they are trying to avoid a sure loss.
Is loss aversion real?
It is one of the most replicated ideas in behavioral economics, and meta-analyses put its average size near 2. Researchers still debate how general it is: the effect is weaker for small stakes and some findings may reflect status-quo bias instead.
Cite this page
Behavioral Economics Lab. "Loss Aversion – Definition, Examples & Evidence." Behavioral Economics Lab, https://www.behavioraleconomicslab.com/biases/loss-aversion.