Moreover, technological change and globalization have reduced the share of middle-skill jobs in overall employment, while the share of lower-skill jobs has increased. These trends, along with a falling labor-force participation rate during the last decade, explain the stagnation of middle-class incomes.
此外科学技术变革和全球化减少了中等技能工作在总体就业中的份额，而低技术工种职位的比例则有所增加。这些趋势再加上过去十年中劳动力参与率的持续降低，正好解释了中产阶级收入陷入停滞的原因