In the summer of 1941, at the urging of his old friends Bill Langer and Phinney Baxter, Mason moved over from a wartime assignment in the Office of Production Management to begin laying the economic infrastructure of what would become the new OSS. From the Division of Research and Statistics of the Federal Reserve Board (FRB) he brought Emile Despres to serve as Chief of what was initially called the Economic Group; Despres in turn recruited from the International Section of the FRB his close colleague Chandler Morse, who, as Assistant Chief, completed the triumvirate of economic administrators of the Research and Analysis Branch.