Can anyone tell me whence and why Tjalling Koopmans and/or George Dantzig took this term, "activity analysis," for their Cowles conference at Chicago in June 1949? So far as I can tell from JSTOR, the term was in use (in English) only among theorists of elementary and vocational education in the United States from 1924 to 1950, when for the first time Georgescu-Roegen put it in print about economics, in citing Koopmans's forthcoming collection of essays. Also, can anyone tell me why Koopmans wrote of von Neumann's analysis of "activity" and "activities," when so far as I can tell von Neumann never used these words? John Womack