From 1850 to 1970 or so, rapid technological progress first triggered wage increases in line with productivity gains. Then came the protracted process of income-distribution equalization, as machines, installed to substitute for human legs, and fingers created more jobs in machine-minding, which used human brains and mouths, than it destroyed in sectors requiring routine muscle power or dexterity work.
从1850年到1970年左右，快速的技术进步首先导致工资与生产率同步增长。接着，开始了滞后的收入再分配平等化过程，因为用于取代人类的腿的机器和手指创造了需要用到人类大脑和嘴的机器看管（machine-minding）岗位，数量超过了需要常规肌肉力量或灵巧工作的部门所损失的岗位。而上涨的真实收入增加了闲暇时间，从而提振了笑容和精神产品的需求。