Say I am cleaning out my stuff. Before I learnt about the endowment effect I would go through my things one by one and try to make a decision on what to do with it. Quite reasonably, I would ask myself whether I should throw this away. At this point, although I didn’t have a name for it, the endowment effect would begin to work its magic, leading me to generate all sorts of reasons why I should keep an item based on a mistaken estimate of how valuable I found it. After hours of tidying I would have kept everything, including the 300 hundred rubber bands (they might be useful one day), the birthday card from two years ago (given to me by my mother) and the obscure computer cable (it was expensive).
Now, knowing the power of the bias, for each item I ask myself a simple question: If I didn’t have this, how much effort would I put in to obtain it? And then more often or not I throw it away, concluding that if I didn’t have it, I wouldn’t want this.
Apparently, this works even while reading your mail:
… it works for emails too. If someone sends me a link to an article or funny picture, I don’t think “I must look at that”, I ask “If I hadn’t just been sent this link, how hard would I endeavour to find out this information for myself?”. And then I delete the email, thinking that however fascinating that article on the London sewerage system sounds or that funny picture of a cat promises to be, I didn’t want them before the email was in my possession, so I probably don’t really want them now.