After the war, I returned to Minnesota, from which I soon moved to Brown University, and a year later, to Columbia University where I remained from 1947 until 1958.
The Chicago Economics Department was in intellectual ferment, although the central issues of the 1930's were very different from those in later times. I had never before encountered minds of that quality at close quarters and they influenced me strongly.
Even before I came to Chicago, I had gotten interested in the existence of dispersion of prices under conditions which economic theory said would yield a single price.
In the 1950s, I proposed the survivor method of determining the efficient sizes of enterprises, and worked on delivered price systems, vertical integration, and similar topics.
And yet I would not freely exchange my science for those of my fellow laureates. They are forever confined in their professional discussions to the small numbers of their fellow scientists.
The delicate and intricate pattern of competition and cooperation in the economic behavior of the hundreds of thousands of citizens of Stockholm offers a challenge to the economist that is perhaps as complex as the challenges of the physicist and the chemist.