I was rereading the article Keynes And The Management Of Real National Income And Expenditure by Wynne Godley from 1983 (page 157 in that book, footnote 20) and he reminds us of this letter from JMK published in The Collected Writings Of John Maynard Keynes, Volume XXVI, pages 287-289, that he thought that import controls work much better than movements in the exchange rates.

To J. M. FLEMING, 13 March 1944

Dear Fleming,

Your paper on quotas versus depreciation, sent me with your letter of February 14th, raises a very interesting question. But, for my own part, I am not one of the’ most economists’, to whom in paragraph 2 you attribute the view that disequilibrium ought, so far as possible, to be corrected by movements in the rate of exchange rather than by controls over commodity trade.

There is, first of all, to the contrary the simple-minded argument that, after all, restriction of imports does do the trick, whereas movements in the rate of exchange do not necessarily do so.

…