ECONOMIC GROWTH CENTER

                  YALE UNIVERSITY

                  P.0. Box 208269
                27 Hillhouse Avenue
              New Haven.  CT 06520-8269


             CENTER DISCUSSION PAPER NO. 773




         LONG-RUN STRUCTURAL AND PRODUCTIVITY CHANGE
                   IN U.S. AGRICULTURE:
              EFFECTS OF PRICES AND POLICIES




                    Robert E. Evenson
                     Yale University

                    Wallace B. Huffman
                   Iowa State University



                         June l997




Note: Center Discussion Papers are preliminary materials circulated to
      stimulate discussions and critical comments.

      Support was provided by the Yale University Economic Growth Center and
      the Iowa Agriculture and Home Economics Experiment Station.

      The authors thank M. Ann Judd at Yale University for data analysis and
      Alan McCunn at Iowa State University with constructing state
      specialization indexes.

                           Abstract


            Long-Run Structural and Productivity Change in U.S.
                Agriculture: Effects of Prices and Policies


               by Wallace E. Huffman and Robert E. Evenson



     The paper presents (1) a conceptual framework for structural change when

farms may be multiproduct or specialized and (2) an econometrics examination

of causes of structural and total factor productivity (TFP) change for U.S.

agriculture.  Farm size, farm specialization, and part-time farming are the

structural dimension emphasized, and they become potential channels to TFP

change.  Using state aggregate data starting in 1950, we conclude that input

prices, public and private research, public extension, and government commodity

programs have directly and indirectly caused change in U.S. farm structure and

TFP.  Our results suggest that changes in farm size, however, have been

dominated by input price changes rather than by technology or government

programs.





Key Words:    farm structure, productivity, farm size, farm specialization,
              part-time farming, research, technical change, agriculture