In 1957, American economists found out that between 1909 and 1949, in the growth rates among the non-agricultural sector, skills contributed 87.5 per cent towards growth, while labor and capital contributed a mere 12.5 per cent.

• 到了1957年，美国经济学家发现，从1909年到1949年，在美国非农业部门生产力的增长中，技术的因素占了87.；5%25，而劳动和资本的贡献仅占12