Economic concept where turning something down heightens emotional attachment For example, say a person has turned down an offer for a competing position with another company. That person now has an increased sense of attachment to their current position with the logic "I turned down that offer, I must really like my current job". 

This sometimes looks a little like sunk cost "I just watched the first 9 out of 10 seasons of this television show. I must really like it, so I'll watch the 10th"

What's the name of this economic concept? Is this maybe a psychology concept instead?
It's called reference-dependent preference, a notion belonging to the intersection of economics, psychology, and neuroscience. Here is a set of brief introductory slides on the concept