Although there is some evidence that Matthew Rabin existed before 1990, we had the pleasure of discovering him for ourselves when, in the early 1990s, he sent each of us a copy of his manuscript "Incorporating Fairness into Game Theory and Economics" [2]. Matthew was, at this time, an assistant professor in Berkeley's economics department, having recently finished his graduate training at MIT. The paper was remarkable in many ways, and it induced us both to call around and ask: "Who is this guy Rabin?" Now, just a decade later, we find ourselves writing an article in honor of his winning the John Bates Clark award. So, who is this guy