Why Do Things We Build Ourselves Feel More Valuable?

After assembling a storage box from instructions, people often like it more than an identical box assembled by someone else, and may even assign it a higher price. Researchers call this rise in valuation from participating in production the ‘IKEA effect’.

In experiments by Norton, Mochon and Ariely, participants assembled boxes, Lego models or origami and then evaluated them alongside people who had not made the items. The increase was not simply a matter of tailoring the object to personal taste: it could appear even when the construction steps were standardised. Successful completion was particularly important. In the original research, incomplete creations, or creations that were later taken apart, did not receive the same boost. The sense of competence from finishing a task and the psychological ownership of ‘I made this’ may both contribute.

This is not supported by only one experiment. A meta-analysis published in a 2026 journal issue synthesised 55 effects involving 5,454 participants. It reported a significant moderate average effect of self-assembly on valuation (d = 0.57), along with associations involving liking, self-concept and ownership. An average effect, however, does not mean everyone overvalues every creation, nor does it show that a particular homemade item is objectively better.

The IKEA effect also differs from the ownership effect, which does not require personal labour, and from sunk cost, which concerns how past investment distorts decisions about further investment. A practical response is to separate ‘I enjoyed completing this’ from ‘how well does it actually work’, then ask someone who did not help make it to assess it independently.

https://doi.org/10.1016/j.jcps.2011.08.002
https://doi.org/10.1002/mar.70064