Bad riddance or good rubbish? Ownership and not loss aversion causes the endowment effect

People typically demand more to relinquish the goods they own than they would be willing to pay to acquire those goods if they did not already own them (the endowment effect). The standard economic explanation of this phenomenon is that people expect the pain of relinquishing a good to be greater than the pleasure of acquiring it (the loss aversion account). The standard psychological explanation is that people are reluctant to relinquish the goods they own simply because they associate those goods with themselves and not because they expect relinquishing them to be especially painful (the ownership account). Because sellers are usually owners, loss aversion and ownership have been confounded in previous studies of the endowment effect. In two experiments that deconfounded them, ownership produced an endowment effect but loss aversion did not. In Experiment 1, buyers were willing to pay just as much for a coffee mug as sellers demanded if the buyers already happened to own an identical mug. In Experiment 2, buyers’ brokers and sellers’ brokers agreed on the price of a mug, but both brokers traded at higher prices when they happened to own mugs that were identical to the ones they were trading. In short, the endowment effect disappeared when buyers were owners and when sellers were not, suggesting that ownership and not loss aversion causes the endowment effect in the standard experimental paradigm.