Multifactor productivity indices that are measured using data envelopment analysis are compared with indices measured using a Cobb-Douglas production function. Cobb-Douglas functions are then used to measure the relative impacts of input growth and productivity on agricultural output growth. Both input growth and productivity growth have accounted for agricultural growth in developed countries. However, in developing countries output growth can primarily be attributed to the growth in fertilizer and machinery. Productivity growth has fallen in many developing countries.