I've had the privilege of interacting with a number of very smart people over the years. Kenneth Arrow was unquestionably the most brilliant person I ever met. He was my teacher for a third of my first-year graduate micro sequence at Stanford, and I saw him at social gatherings roughly annually since then. In addition to being arguably the most important economist since Keynes, he was good company: charming, funny, and cultured.
There will be plenty of Arrow anecdotes in days to come, and many reckonings of his place in the history of economic thought; the New York Times obituary is a good place to get a sense of just how broad, deep, and influential he was. But I feel compelled to offer a few personal observations.
When I was deciding on grad schools, my advisor at UMass was pushing Stanford. I was interested in radical/Marxist economics, and Stanford was one of the top departments where you could study that stuff in the early 80s. "And of course you know Arrow is there," he said. I really didn't know enough about economics to fully appreciate what he meant. But I went.
First observation: Kenneth was not a great teacher. He taught us general equilibrium theory. (That would be a little like learning relativity from Einstein.) His presentation was adequate, and of course technically accurate. But one sensed he was a little bored teaching foundational proofs he had derived several decades earlier. Late in the term he turned to the optional part of the syllabus, where he had decided to include some material on endogenous preferences and new developments in what would in a few years come to be known as behavioral economics. He became animated. He quoted from The Odyssey. Suddenly we were in the presence of a great mind, working things out for himself, and sharing it with us. Hmm... maybe a great teacher after all.
He was consistently a man of the left, a social democrat (or democratic socialist?). That's a good thing, by the way. He dressed funny. His belt was always up around his armpits. He rode his 3-speed to campus and sometimes forgot to remove his pants clip. He didn't seem to have an empirical bone in his body; as a devoted empiricist myself, this has given me pause on a number of occasions– maybe facts and data are not the same thing...
My favorite Arrow story is from the annual Christmas caroling party we both attended. I pride myself on knowing a lot of the classic Christmas carols, even beyond the first verse. Not bad for a lapsed Unitarian! Kenneth, Jewish, put me to shame. He knew most of the carols by heart, often deep into the third or fourth verse. (How?) His singing voice was not good, to say the least. I will miss him.