At Chicago, I was in the midst of a veritable galaxy of stars: Trygve Haavelmo, Tjalling Koopmans, Theodore Anderson, Leonid Hurwicz, Herman Rubin, Kenneth Arrow, Don Patinkin, Herman Chernoff, and Herbert Simon, among others. I completed my first of a series of macroeconometric models, solidified my understanding of econometrics, learned (through endless discussion) about the functioning of the economy, and got started on several theoretical paths such as aggregation, demand systems, and prediction.