Dale Jorgenson, of Harvard University, President of the American Economic Association in 2000, concludes that: 'Griliches and I showed that changes in the quality of capital and labor inputs and the quality of investment goods explained most of the Solow residual. We estimated that capital and labor inputs accounted for 85 percent of growth during the period 1945–1965, while only 15 percent could be attributed to productivity growth… This has precipitated the sudden obsolescence of earlier productivity research employing the conventions of Kuznets and Solow.'