Lawrence R. Klein 1920-2013: Notes on the early years

Klein can well be said to have created the field of macroeconometric modeling almost singlehandedly. His international influence started at an early stage. The article offers scattered archive observations on Klein's early years from undergraduate study to the University of Pennsylvania in 1958. Klein was in 1944 recruited by the Cowles Commission in Chicago to construct the first macroeconomic model in the USA, drawing on the experiences of the interwar modeling work of Jan Tinbergen and the new path-breaking econometric methods developed by Trygve Haavelmo. The first Klein model was taken into use at the end of 1945 to shed light on the prospects for the US economy in the transition from war to peace. After two-three years in Chicago Chicago, Klein traveled for a year in Europe and initiated macroeconometric modeling work in Canada, at the University of Michigan, and at Oxford University. This was only the beginning of the lifelong influence exerted on modelers around the globe. The article pays attention to Klein's relation to Paul Samuelson, Jacob Marschak, Trygve Haavelmo, Ragnar Frisch, and others.