William Sandholm, known to many of us as Bill, and former council member of the Society, passed away on July 6th, 2020. At the time of his death he was the occupant of the Richard E. Stockwell Chair in Economics at the University of Wisconsin.

Bill made a number of important contributions to Game Theory starting with his extension of the notion of potential games to a setting with a continuum of players but finite strategy sets and his introduction of the idea of evolutionary implementation. Over time he acquired a reputation, justly deserved, as an authority on evolutionary game theory. Many members will be aware of his book, “Population Games and Evolutionary Dyanamics” which circulated in samizdat form well before it appeared in print in 2011, at which point it became the standard reference for population games. One reviewer on Amazon described the book as `not just a monograph of finished research projects but (literally) an introduction for new future researchers in EGT.’  Throughout, his work was characterized by insight and elegance.

Bill was also a selfless professional citizen.  He served on the board of virtually every game theory and economic theory journal, he wrote and made freely available software for working with evolutionary dynamics, he organized meetings and served on panels, and he worked patiently and creatively with students.  His enthusiasm was coupled with a gentle manner and constant consideration for others.  Interactions were always better when he was in the room.  He will be sorely missed.