I was discussing Root, and its similarities and not similarities to COIN in another post with Brian Train, and he pointed me to this article analoggamestudies.org – Affective Networks at Play: Catan, COIN, and The Quiet Year by Cole Wehrle (designer of Root) in which he explores game design in terms of the emotional experiences created by play. It sounds like he was very successful at following that line of design, based on your report.