672. Joan Robinson to Harrod , 3 June [1937] [a]
[Replies to a letter not found; follows on from 671 , continues at 675 ]
3, Trumpington Street, Cambridge #
I now feel that I have misunderstood you from the start and put your neutrality at the wrong point in my map. In order to elucidate [b] the nature of your neutral invention would you tell me what change in the rate of interest would be required to prevent capital per unit of labour from altering in face of a neutral invention? (I have thought all along the answer was nil & this is evidently where I went off the rails)
May I offer you once more my humble thanks for your excessively kind remarks in E.J.? [1]