The IKEA Effect
As a Designer and Product Consultant, one of the most common traits I see in product teams is an unwillingness to throw away the things they've made. Some of the teams I've worked with celebrate removing lines of code, but more often then not, people believe that what they made is too valuable to throw away (even if it can be brought back using Github, Abstract or the myriad other forms of version control.)
The feeling of sunk costs comes in many forms: you might care what others think of you or that you'll regret quitting because you might be on to something. What I encounter most often is a team that feels their work is too valuable to toss. This is known as the IKEA effect: labor equals valuation.
The IKEA effect was coined by Michael I. Norton a, Daniel Mochon and Dan Ariely after conducting a study on how labor affects valuation. They captured their findings in the paper The IKEA Effect: When Labor Meets Love.
The researchers set up four studies in which they had the participants assemble IKEA boxes, fold origami, and put together sets of Legos. The researchers found that participants viewed their amateur creations to have equal value to that of an expert's creation. Moreover, they expected others would feel the same.
Participants saw their amateurish creations as similar in value to experts' creations and expected others to share their opinions.
Michael I.Norton, Daniel Mochon and Dan Ariely
However, if the participants were asked to destroy their creation as part of the task, or failed to complete the assembly, the feeling of value was gone. The conclusion was that labor leads to love when labor results in successful completion of tasks, and that labor increases valuation for both “do-it-yourselfers” and novices.
If you're ever on the fence about tossing a feature or throwing out some code, ask yourself if you see value in it because you built it. Don't let sunk costs sink you (sorry for that closing bit).