Among the letters of comment Keynes received after the publication of the Treatise was one from Bertil Ohlin. Keynes's reply is of some interest.

To PROFESSOR B. OHLIN, 5 January 1931

Dear Professor Ohlin.

Thanks very much for your letter of December 31. I am most happy that you find matters of interest in my book. My own feeling is that now at last I have things clearer in my own head, and I am itching to do it all over again. I am sorry that my ignorance of Swedish should have kept me in ignorance of the work of Davidson and others. As to your point that reparations cause a shift in the demand curve of the receiving country, irrespective of any rise in the price level of that country, I do not think I disagree with you.

On the matter of the Wicksell essay, I am rather horrified to contemplate such a long further delay. Is it a matter which would really take you much time once you settled down to it? A delay of six months I should not mind. But a delay of a full year, and even then some measure of uncertainty, seems to me rather formidable. Could you not consider whether this might not be slipped in, now that you have got your book out of the way, along with your work for the League of Nations? As for Dr. Lindahl, I am, unluckily, quite ignorant of his personality and his qualifications.