I am honored to be included in this distinguished series. I am also pleased to be included as an old friend of Nancy Schwartz. Nancy, Morton Kamien, and I were colleagues at Carnegie Tech, some twenty years ago - all three of us engaged in learning and applying the mathematics of optimal-control theory to economic dynamics. Younger faculty at Northwestern knew Nancy as a coauthor of the leading advanced text in the economic applications of control theory and (with Mort) as the foremost proponent of applying these methods to problems of industrial organization. You probably thought she was born knowing this material. But I can tell you that when we came to Carnegie none of us knew an Euler equation from a transversality condition, and everything we did was an exercise in learning by doing. Those years were a great learning experience for me, and it was incredibly lucky for me to have a colleague as smart, as serious, and as helpful as Nancy always was. It is good to have an occasion to express my debt to her publicly, and I thank you for this opportunity.