Now hours per person are shrinking, first because of the retirement of the baby boomers, and second because there's been a very significant dropping out of the labor force of prime age adult males who are in the bottom half of the educational distribution.
人均工时不断缩水， 原因之一是五六十年代婴儿潮出生的人目前已面临退休， 原因之二是青壮年男性劳动力的比例 大幅度下降， 他们是教育分布的下半部。