On Joan Robinson’s role in creating the myth that R. Kahn originated the multiplier concept

An enduring myth accepted by all Orthodox and heterodox economists is that it was Richard Kahn who discovered originated the concept of multiplier. then supposedly showed Keynes how multiplier could be specified mathematically so as to provide hard support for Keynes’s views in late 1920’s about increased initial government spending on public infrastructure generating much larger increases total than original injection, leading decreasing levels unemployment. There are three major problems with this story. First, Kahn, himself, a 1936 response Hans Neisser Review Economics Statistics stated most his ideas came from Keynes. Second,the mathematical logical development had already been formalized formulated precisely 1921 p. 315 footnote 1 A Treatise Probability section 8 chapter 26. Third, provided an arithmetic example technique worked out May,1929. simply no foundation myth, promoted Joan Robinson, author concept. went along Robinson because he involved 54 year old relationship Robinson. Keynes taught theory left up write full blown article it, which published June,1931 issue Economic Journal.