The Endowment Effect

What Is The Endowment Effect?

The endowment effect is the tendency for people to value something more highly simply because they own it. Documented experimentally by Richard Thaler together with Daniel Kahneman and Jack Knetsch, it describes how people demand substantially more to give up an object they already possess than they would be willing to pay to acquire the same object. In classic experiments, participants given a mug required a much higher price to sell it than others were willing to pay for an identical mug. The effect is closely tied to loss aversion: parting with something one owns is felt as a loss, which looms larger than the foregone gain of not acquiring it.

Why It Matters

The endowment effect challenges a basic assumption of standard economics, that a person's valuation of a good should not depend on whether they happen to own it. Because it does depend on ownership, markets can be stickier than simple models predict, with people reluctant to trade even when doing so would make them better off. The effect helps explain behavior in settings from real estate to financial portfolios to free-trial marketing, where possession itself raises perceived value. It also bears on policy design, since how rights and default ownership are assigned can shape outcomes. The finding contributed to Richard Thaler's recognition as a founder of behavioral economics.