The exaggeratedly high value and attachment placed on products that one builds themselves, regardless of the end result quality.
Coined by Michael Norton, Daniel Mochon and Dan Ariely in a 2011 paper in the Journal of Consumer Psychology, because products from the Swedish manufacturer typically require some assembly. (source)
This idea taps into something very primal — that we come to more highly value that which we have a hand in making. This can be true for furniture, but also for our projects, our side hustles, our artistic expressions, our labor's of love. And that's not necessarily a bad thing, either! We should value that which we spend more time working on, and bringing into the world -- but the trick is not to overvalue it either, and to let our pride get in the way of our reason.