With great shock and sorrow, we have received the news that Gregory Kersten passed away on May 26, 2020.

Gregory was the heart and soul of the GDN community, and has served our community in many indispensable ways. He was president of the GDN section 2017-2019 and editor in chief of the GDN journal since 2016. For many of us, he was the one who sparked our interest in the topics of group decisions and negotiations. His scientific contributions to the field were numerous. To name but a few, he developed models and algorithms for group decision making; he designed the first web-based negotiation support system Inspire, which he generously shared with the community; he made important contributions to empirical research on (e-)negotiations.

We will always remember Gregory as an outstanding researcher, for his extraordinary and dedicated services to the GDN community, and most of all as a true friend.