50 Years of Aumann’s Agreement Theorem

One of the most popular posts in this blog’s history was Common Knowledge and Aumann’s Agreement Theorem, based on a lecture that I gave to high-school students 11 years ago. One of the impacts of that post, I’m proud to say, is that (according to Steven Pinker) it helped to inspire Steve’s excellent recent popular book, which you should read, entitled What Everyone Knows That Everyone Knows…: Common Knowledge and the Mysteries of Money, Power, and Everyday Life. Two weeks ago, I was privileged to attend a workshop in Paris on “50 Years of Agreeing to Disagree,” where (among other things) I got to meet the 96-year-old Economics Nobel Laureate Robert Aumann for the first time. Me and my friend Aran Nayebi (CS professor at CMU) with Robert Aumann I got to catch up there with Steven Pinker as well, who gave a phenomenal talk on the psychology of common knowledge. My own talk was entitled The Complexity of Agreement, with New Directions and Applications (link goes to my PowerPoint…