implications of current agricultural policies on efficiency, productivity, and competitiveness in the sector, and consider …. The Effects of Subsidies on Farm Productivity and Efficiency of Production.- Subal Kumbhakar and Gudbrand Lien .- 7. RD … and U.S. Agricultural Productivity: A State Panel Approach.- V. Eldon Ball, Rolf Färe, Shawna Grosskopf, and Dimitri …