Once I showed him a peculiar way of using Bayesian methods to discipline a model — an approach which, as far as I can tell, nobody has found interesting but Chris. I tried explaining myself. He looked at me, slightly puzzled or bemused. He leaned back in his chair and his mind wandered: Hmmm, interesting. We discussed it briefly, and of course he grasped what I had in mind immediately — an experience I have rarely encountered since with regard to this approach. A few days later I received an email — not particularly long. It showed how I could use exactly the same approach by relaxing one of the assumptions he thought might be unappealing. Who does that?! Chris Sims. He was the classic intellectual, and he never put on airs. I was visiting Princeton for a year around 2010 and was incredibly lucky. I got the office next to his. One of my assignments was to advise undergraduate students. I was advising one doing finance, which I know little or nothing about. As his deadline approached, the student had a question about econometric interpretation. “Why don’t you ask Chris?” I suggested. His eyes widened and he looked like a deer in the headlights. Chris Sims??!! Yes, he’s right next door — let’s see what he says. And sure enough, there was Chris, immediately interested, even though the question was just as far from his area as it was from mine. I wish I remembered the details, but the paper looked completely different after consulting Chris — he literally turned it upside down. I heard later that people in the finance department at Princeton had been very excited about the paper and that it won a major prize. That was what a few minutes with Chris could give you. This generosity with his intellect and his ideas was universal. I recall once reading the seminal paper by Finn Kydland and Edward Prescott on rules versus discretion — a paper that revolutionized economics by brilliantly illustrating the problem of dynamic inconsistency, one of the key contributions cited by the Nobel committee when they received their richly deserved prize. I still recall my bewilderment sitting in the Princeton library and reading it as a graduate student, since my dissertation built on it. Footnote 1 of the paper says: “The original objective of this research was to demonstrate the applicability of optimal control methods in a rational-expectations world. We recognized the non-optimality of the consistent solution obtained by using control-theory techniques, but initially considered this a minor problem. Further thought, in large part motivated by C. A. Sims’s criticism of our initial analyses, led us to the radical conclusions of this essay.” To me, Chris had something of an artistic temperament. Conversations would often jump into unexpected places, and his interests were broad. I think whatever he had turned his interest to in life, the result would have been extraordinary. We were just lucky he happened upon economics. His work on VARs in the 1980s laid waste to what existed before. His work on Bayesian methods transformed how we estimate macro models; those methods are in use in every major central bank today. But perhaps the story that best captures what I perceived as his artistic temperament is this one: 2/3