From the 1961 Economics Graduate Program Broschure
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Major Program and General Examinations
Work taken in the Department of Economics and Social Science for the doctorate in economics is divided—broadly speaking—into two separate options: economics and industrial relations. But there is considerable overlap between the two.
All students in both options are examined five fields. Among the fields presently available are the following: economic theory, advanced economic theory, monetary and fiscal economics, industrial organization, economic development, international economics, economics of innovation, labor economics and labor relations, personnel administration, human relations in industry, statistical theory and method, and economic history. Each student selects one field as having primary importance for this professional career; ordinarily this is the field in which he writes his dissertation, though exceptions may be made. The remaining four fields are designated secondary fields. One of the five fields must be economic theory.
Students are also required to have at least a minimum knowledge of statistics and economic history. This minimum is presently interpreted to mean one semester of work in each at the graduate level. Candidates who present statistics or economic history as a primary or secondary field normally take two or three semester subjects in the field and automatically satisfy the requirements in that area.
Additional commentary.