photo: Hayek Teaching at the L.S.E. in 1948

It is not so well known that it [Keynes's and my own Hayek-inspired move from thinking in terms of price-levels and the rate of interest to thinking in terms of inputs and outputs] is matched by a movement from Hayek to Harrod. I once asked Harrod what had put him on to the construction of his so-call ‘dynamic’ theory; he said, to my surprise, that it was thinking about Hayek. — John Hicks