NATIONAL BUREAU OF ECONOMIC RESEARCH INCORPORATED P~~~, • C. Reinold Noyes, Presiden~; Boris Shishkin, Vice-Presidenf;G. B. Roberts, OFFICERS: Shepard Morgan, Ch.arrm~n; M rtha Anderson, Edrfor • T r W J Carson, Execufrve Drrecfor; a b ·~ M A. Copeland Dan•el Creamer, reasure 1 • • • f R h Moses A ramov1 .... , • ' p M k RESEARCH STAFF: Arthur F •• Bums, O~re;t~i; The:;a~~lt~ren, Simon Kuznets, Clarence D. Long, Ruth • ac , Solomon Fabricant, W. B. H•ckman, • • 'R J Sa...