Endowment Effects

In his book Thinking Fast and Slow, Daniel Kahneman discusses an experiment he helped run to explore the endowment effect. The endowment effect is a cognitive fallacy that helps explain our attachment to things and our unwillingness to part with objects, even when we are offered something greater than the objective value of the the object itself. We endow the object with greater significance than is really warranted, and in his book, Kahneman shows that this has been studied with Super Bowl tickets, wine, and coffee mugs.


Kahneman helped run experiments at a few different universities where college students were randomly given coffee mugs with the university logo. The mugs were worth about $6 each, and were randomly distributed to about half of a classroom. Students were allowed to buy or sell the mugs, and the researchers saw a divergence in the value assigned to the mugs by the students who randomly obtained a mug and those who didn’t. Potential sellers were willing to part with the mug for about $7 dollars, a price above the actual value of the mug. Buyers, however, were generally only willing to purchase a mug for about $3, or half the value of the mug.


Kahneman suggests that the endowment effect has something to do with the unequal values assigned to the mug by those who received a mug and those who didn’t. He suggests that it is unlikely that those who received the mugs really wanted a university mug and particularly valued a mug relative to those who didn’t receive a mug. Those students should have been willing to trade the mug for $3 dollars which could be used to purchase something that they may have actually wanted, rather than a random mug. To explain why they didn’t sell their mugs, Kahneman suggests that the mugs became endowed with additional value by those who received them.


A further study showed similar effects. When all students in the class randomly received either a chocolate bar or a mug, researchers found that fewer students were willing to make a trade than the researchers predicted. Again, it is unlikely that a random distribution of mugs and candy perfectly matched the mug versus candy preferences of the students. There should have been plenty of students who could have used a sugar boost more than an extra mug (and vice versa), but little trading actually took place. It appears that once someone randomly receives a gift, even if the value of the gift was very small, they are not likely to give it up. The gift becomes endowed with some meaning beyond its pure utility and value.


Kahneman describes part of what takes place in our minds when the endowment effect is at work, “the shoes the merchant sells you and the money you spend from your budget for shoes are held for exchange. They are intended to be traded for other goods. Other goods, such as wine and Super Bowl tickets, are held for use to be consumed or otherwise enjoyed. Your leisure time and the standard of living that your income supports are also not intended for sale or exchange.”


The random mug or candy bar were not seen as objective items intended to be traded or bartered in exchange for something that we actually want. They were viewed as a windfall over the status quo, and thus their inherent value to the individual was greater than the actual value of the object. Kahneman suggests that this is why so few students traded candy for mugs, and why mug sellers asked far more than what mug buyers wanted to pay in his experiments. The endowment effect is another example of how our emotional valence and narrative surrounding an otherwise objectively unimportant object can shape our behaviors in ways that can seem irrational. Next spring when you are trying to de-clutter your house, remember this post and the endowment effect. Remember that you are imbuing objects with value simply because you happen to own it, and remember that you would only pay half price for it if it was actually offered to you for purchase now. Hopefully that helps you minimalize the number of mugs you own and declutter some of your cabinets.

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