The middle class in America's cities has shrunk dramatically in the 21st century.
美国城市的中产阶级阵容在本世纪大幅萎缩。
A Pew Research Center analysis of Census Bureau data looked at the state of the middle class in America's metropolitan areas. Pew defined "middle-income" households as those whose income fell between two-thirds and twice the national median household income.
皮尤研究中心通过对美国人口普查局数据进行分析，察看了美国大都市区中产阶级的状态。皮尤研究中心对“中等收入”家庭的定义是，收入在全美国平均收入三分之二到两倍之间的家庭。
Between 2000 and 2014, 203 out of the 229 metropolitan areas analyzed had a decline in the percentage of their populations that fell in that middle-income range.
2000年到2014年间，在其分析的229个大都市区中，有203个大都市区的中等收入群体所占人口比重有所下降。
Pew observed that the decline in the middle class is associated with an overall increase in inequality in the US.
皮尤发现，中产阶级的衰落与美国的不平等现象全面增长有关。

Pew also noted that the drop in the percentage of households that fall in the middle coincides with an overall decline in incomes. Pew's report pointed out that in the time period covered, real median household incomes in the US as a whole fell by 8%.
皮尤还发现，中产阶级家庭比例的降低与收入的全面下滑相吻合。皮尤的报告指出，在研究覆盖的时间段内，美国实际家庭收入中位数整体跌落8%。
The decline of the middle class in America's cities is one of the biggest political and economic problems of the 21st century, and Pew's analysis shows the severity of the problem.
美国城市中产阶级的下降是二十一世纪最大的政治和经济问题之一，而皮尤的这一分析表明了问题的严重性。
"The current and future status of the American middle class continues to be a central issue in the 2016 presidential campaign. Moreover, new economic research suggests that a struggling middle class could be holding back the potential for future economic growth," Pew wrote in its report. "The national trend is clear — the middle class is losing ground as a share of the population, and its share of aggregate U.S. household income is also declining."
皮尤研究中心在报告中写道：“美国中产阶级的当前和未来的地位仍然是2016年总统竞选中的一个核心问题。此外，新的经济研究表明，一个正在挣扎的中产阶级可能会阻碍未来经济增长的潜力。这个国家的趋势是明显的--中产阶级正失去作为一部分人口的份额，它的总收入也在下降。”