Letters and speeches of Orval Adams, Lewis H. Brown, Stuart Chase, J. I. Craig, James H. R. Cromwell, Cyrus S. Eaton, William Trufant Foster, Rudolph Hecht, B. E. Hutchinson, R. C. Leffingwell, Walter Lippmann, Thomas I. Parkinson, J. David Stern, and Robert P. Vanderpoel. These materials discuss economic ideas. The catalysts for many of the letters are often books, articles, or speeches.