"You don’t need to be an economic historian. Wicksell, Marshall, Pigou, Cassel, Hawtrey, Fisher, etc, all had business cycle explanations that involved what we would call “demand shocks,” even if they didn’t all use that term. Fisher invented the Phillips Curve in 1923. Keynes was inaccurately describing the standard business cycle model of the 1920s, and it’s hard to see how it wasn’t intentional, at least at some level. He personally knew some of these people. Maybe that’s why he didn’t quote them directly."That's odd. I seem to recall Keynes citing Wicksell, Marshall, Pigou, Cassel, Hawtrey, and Fisher - the exact crew that Sumner picks out here - quite favorably as antecedents to his ideas. Pigou comes in for criticism in the beginning too, of course - we all know that.
To take Sumner's phrase, "it's hard to see how it wasn't intentional, at least at some level". How can you cite the people that Keynes explicitly related to his own ideas and then accuse him of exactly the opposite?