Technological Progress and Productivity GrowthTechnological progress shifts the productivity curve upward. Here we hold human capital per worker fixed. We assume that the lower curve (the same curve as in FIGURE 38.1) reflects technology in 1940 and the upper curve reflects technology in 2010. Holding technology and human capital fixed, quadrupling physical capital per worker from $20,000 to $80,000 leads to a doubling of real GDP per worker, from $30,000 to $60,000. This is shown by the movement from point A to point C, reflecting an approximately 1% per year rise in real GDP per worker. In reality, technological progress shifted the productivity curve upward and the actual rise in real GDP per worker is shown by the movement from point A to point D. Real GDP per worker grew 2% per year, leading to a quadrupling during the period. The extra 1% in growth of real GDP per worker is due to higher total factor productivity.