Trap/Behavioral Economics/No. 0326
Endowment Effect
The endowment effect is the tendency for people to value an item more when they own it than when buying it. Named by Richard Thaler in 1980, it is often studied in behavioral economics through gaps between willingness to pay and willingness to accept.
- Evidence
- Mixed evidence
- Read
- 6 min
- Links
- 7 connections
- Useful when
- Deciding under uncertainty · Designing products · Money and investing · Negotiating
01You've seen this when…
- in life
A jacket you rarely wear stays in your closet. You turn down a $40 offer, although you recently passed on the same model secondhand for $30.
- at work
Your department receives a spare 3D printer it never requested. A month later, it refuses to transfer it to another team unless the price exceeds what it would have paid to get one.
- out in the world
A town receives an empty lot in a land swap. Council members reject a sale offer as far too low, although they recently declined to buy a comparable lot for that amount.
02The idea
Before something is yours, you weigh whether it’s worth acquiring. Once it’s yours, you weigh whether it’s worth surrendering. Those can produce surprisingly different answers, even when the object hasn’t changed.
The endowment effect is an increase in the value you assign to something because you own or possess it. Researchers often measure it by comparing willingness to pay, the most someone would spend to acquire an object, with willingness to accept, the least someone would take to give it up.
Ownership can push the second number above the first. A mug that wasn’t worth buying becomes too valuable to sell.
Ownership distinguishes this effect from status quo bias, which favors the current arrangement regardless of ownership. The IKEA effect links value to the effort put into something. Simply receiving an object can be enough for the endowment effect.
But a buying–selling gap is a clue, not a diagnosis. Budgets, replacement costs, bargaining and attachment can also produce one.
03Why it happens
- Keeping it becomes the baseline. Once you own the object, keeping it feels like the normal outcome. From that baseline, selling the object for money feels like a loss. This is reference dependence: the starting point changes how you evaluate the choice. Loss aversion is one influential explanation for why giving something up can loom larger than acquiring it.
- Ownership can create attachment. You associate your possessions with your identity and connect them to your intentions or memories. Even a recently acquired object can start to feel specially suited to you. Attachment can increase its appeal independently of a conscious fear of loss.
- Buyers and sellers examine different things. A buyer looks at the price and weighs the purchase against competing products and other uses for the money. An owner notices the object’s useful features and reasons to keep it. The same transaction gets evaluated through different information.
These explanations can overlap. There isn’t one settled mechanism behind every result called an endowment effect. In particular, finding that owners demand more money doesn’t, by itself, establish that loss aversion caused the difference.
04A worked example
In experiments published in 1990, Daniel Kahneman, Jack Knetsch and Richard Thaler randomly gave some participants mugs. Other participants could buy them. The researchers then elicited the prices at which people would trade.
What it looks like The sellers happen to like the mugs more than the buyers do. They want substantially more to part with them than buyers are willing to spend.
What’s actually going on Random assignment makes a systematic difference in prior tastes unlikely. Having the mug appears to change its valuation. In another condition, participants chose between a mug and cash without first owning the mug. Their valuations were closer to buyers’ than sellers’, suggesting that the result required an explanation beyond reluctance to spend money.
The experiment made ownership’s influence visible using an ordinary object with less personal history than a family heirloom. It left some possible explanations unresolved. Later experiments showed that instructions and procedures for eliciting prices can substantially change the result.
What would have helped Outside the experiment, record your valuation before taking possession. When deciding whether to sell, compare that earlier judgment with what changed: new information, actual usefulness, replacement costs—or just the feeling that it’s now yours.
05How to spot it
These are prompts for investigation. Whether you should sell remains an open question.
06What to do instead
- Reverse the transaction. Imagine you don’t own the object, but have the cash someone is offering. Would you spend that cash to acquire it? This consider-the-opposite strategy exposes differences that possession can hide.
- Check completed transactions. Look at what comparable items actually sell for. Other owners’ asking prices can contain the same premium as yours.
- Give the alternative equal attention. Write down what selling would fund, free up or simplify. Keeping something has an opportunity cost, even when it requires no new payment.
- Separate attachment from practical costs. List moving expenses, taxes, retraining and other real switching costs. Then identify any remaining premium that comes only from not wanting to let go.
- Set a valuation before possession. Before accepting a free trial or taking an item home, record what you’d pay for it. Revisit that figure later rather than starting the assessment from scratch.
07When it isn’t a trap
A possession can be worth more to you than its market price. Your grandfather’s watch isn’t interchangeable with an identical watch online. A familiar tool may save you time that a replacement won’t. Keeping these can be sensible.
Budgets also matter. Someone may lack the money to buy an item yet require substantial compensation to give it up. Economic theory allows buying and selling valuations to differ under some conditions; equality isn’t a universal test of rationality.
Experience changes the picture too. Research with experienced traders has found smaller endowment effects in some settings. Other experiments have removed the usual valuation gap through clearer instructions and carefully designed procedures. Neither ownership nor a high asking price guarantees a bias.
The trap is an ownership premium that goes unexamined. Caring about your possessions can be reasonable, and so can negotiating firmly or refusing a bad offer.
08Roots
In his 1980 paper, economist Richard Thaler described a wine collector who turns down a generous offer for bottles he already owns, although he wouldn’t spend anything like that amount to acquire them. The wine merchant’s offer made the puzzle concrete: why did buying and selling seem to involve different valuations of the same bottles?
Thaler named the pattern the endowment effect. An endowment here means what someone starts with, regardless of whether it came as a gift or inheritance. Working with Kahneman and Knetsch, he helped turn the puzzle into controlled experiments. Ordinary mugs allowed researchers to assign ownership directly, bypassing the wait for people to acquire possessions themselves. That made it possible to separate ownership from preexisting tastes.
One adaptive hypothesis is that reluctance to surrender possessions could have helped people protect useful resources when replacement was uncertain. That’s a speculative account of the effect’s history. The experimental findings leave open whether such a tendency evolved for that purpose. The firmer lesson is narrower: possession can change valuation, and the setting matters.
09How solid is this?
Ownership-related valuation differences are well documented, but their size and explanation vary. Some experiments remove the usual buying–selling gap through different instructions and procedures, and trading experience can reduce it. A gap alone does not prove irrationality or loss aversion.
10Connections
- Often confused withIKEA Effect, Loss Aversion
- Countered by Consider-the-Opposite Strategy
- Part of Status Quo Bias, Reference Dependence
- See also Opportunity Cost, Switching Costs
11Origin and sources
Richard Thaler named the endowment effect in 1980. Daniel Kahneman, Jack Knetsch and Thaler developed influential experimental demonstrations published in 1990.
- [1]Thaler, R. (1980). Toward a positive theory of consumer choice. Journal of Economic Behavior & Organization, 1(1), 39–60.
- [2]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.
- [3]Plott, C. R., & Zeiler, K. (2005). The Willingness to Pay–Willingness to Accept Gap, the "Endowment Effect," Subject Misconceptions, and Experimental Procedures for Eliciting Valuations. American Economic Review, 95(3), 530–545.
- [4]List, J. A. (2003). Does Market Experience Eliminate Market Anomalies? The Quarterly Journal of Economics, 118(1), 41–71.
- [5]Morewedge, C. K., & Giblin, C. E. (2015). Explanations of the endowment effect: an integrative review. Trends in Cognitive Sciences, 19(6), 339–348.
Suggest an edit· Updated 2026-10-02