Peter Zorn

When I was a grad student, the word got out that Chris decided to give a seminar at the department. It caused considerable excitement. It was unusual for professors to give internal seminars. Chris began his talk something like this: “I was thinking back to my undergraduate thesis the other day,” — but Chris studied mathematics when he went to college at Harvard, graduating in 1963. He had written his undergraduate thesis on Shannon capacity, the idea that noise places a limit on how much useful information can be extracted from signals. I do not know what application he pursued at Harvard almost forty years earlier. But at that Princeton seminar he applied his undergraduate thesis to the study of optimal consumption when information-gathering is costly using the tools he had developed. An enormous literature has emerged from Chris’s undergraduate thesis, now known as rational inattention. Had he not already revolutionized economics in other ways, that literature could be grounds for a Nobel Prize in itself. I recall that after the seminar, we, the graduate students, were in a daze. That was based on his undergraduate thesis?! We all knew how significant the work was — even if, truth be told, we were hanging on by the skin of our teeth to grasp it. A number of Princeton students who were at that seminar, and others who arrived a few years later, built successful careers on Chris’s undergraduate thesis. Before I end, a word on his humanity and intellectual integrity — for these too were an expression of the same thing. To me as a student, he was a warm, fatherly figure. I was therefore genuinely flabbergasted when, after graduating, I realized that people who did not know Chris well seemed a bit afraid of him. Chris?! But there was a reason. A fundamental feature of Chris was intellectual integrity. He would simply say exactly what he thought was right, whether in discussing or refereeing papers by his own students or anybody else. And this is rare — our profession is full of games, strategic positioning, and calculated moves for career advancement. I don’t think that sort of thing ever occurred to Chris. So when Chris sent me an email the day before my dissertation defense telling me “I do not think your equilibrium concept makes any sense” — a central part of the thesis — this was not a source of terror but of pure excitement, for then I could argue with him about it: an excellent excuse to bother him more and pay a visit to Princeton, since I had by then moved on to another job. Alas, the issue was settled, and to my disappointment I had to find different excuses to get in touch. The classic Hollywood ending of the relationship between the master and the mentee is the moment when the mentee manages, in some way, to surpass his teacher. I am afraid I never had that Hollywood ending. One of the last time I met Chris, we had lunch at the American Economic Association. Even after more than two decades since I had been his student, he seemed exactly the same, and the conversation was of course purely economics — me hanging on to every word — asking obscure technical questions. Now that I look back, if anybody had told me at the time he was close to 80 I’m not sure I would have believed it. To the very end, his intellectual fire never cooled. 3/3