Correspondence, research materials, publications, memos, and reports of two Middle East economic missions in which Barker participated. He was first recruited by Overseas Consultants, Inc., an organization formed by eleven of the top U.S. engineering and management firms, to investigate and produce a preliminary report on the feasibility of Iran's Seven-Year-Plan for reconstruction. There is significant correspondence with many important Iranian government officials including Abol Hassan Ebtehaj and Mosharraf Naficy. Barker was responsible for writing a large part of the report and the series contains a rough draft of the report as well as notes and research materials. He also kept a journal of his trip which describes the country, palaces, daily activities, and writing of the report in detail.

In Turkey Barker headed a group sent by World Bank to investigate possible Marshall Plan era investments in reconstruction. These materials pertain more to the personnel and organization of the mission, but does contain a final report written by Barker.