IS-LM "à la Hicks" versus IS-LM "à la Modigliani"

The aim of this paper is to revisit Hicks‚ "Mr Keynes and the Classics" article. It is argued that Hicks' own model, his IS-LL model, is significantly different from the subsequent textbook IS-LM models. In short, Hicks' classical model exhibits involuntary unemployment and allows for monetary expansion to have real effects, features which are absent in subsequent standard models. I also argue that Modigliani's 1944 article has played an important role in recasting Hicks initial model. Thus a distinction ought to be drawn between "IS-LM à la Hicks" and "IS-LM à la Modigliani", modern IS-LM models being molded on the latter. Hence the conclusion that the transition from Keynes' to Keynesian economics is a two-step process, its first stage concerning the passage from the General Theory to Hicks' model, its second stage the shift from Hicks' use of the IS-LM framework to Modigliani's recasting.