In 1941 Hurwicz was helping Paul Samuelson to teach at the Massachusetts Institute of Technology and helping Oskar Lange to teach at the University of Chicago. At Illinois Institute of Technology during the war, Hurwicz taught electronics to the U.S. Army Signal Corps. Then from 1942 to 1944, at the University of Chicago, he was a member of the faculty of the Institute of Meteorology and taught statistics in the Department of Economics. His advisors in 1942 were Jacob Marschak and Tjalling Koopmans of the University of Chicago, who now work for the Cowles Foundation at Yale University.