A study by the economist Homi Kharas of the Brookings Institution gives us a sense of the scale of this change. He estimates that 18% of the world’s middle class lived in North America in 2009, while another 36% lived in Europe.
布鲁金斯学会经济学家荷米·卡拉斯（Homi Kharas）的一项研究向我们展示了这一变革的规模。他首先判断2009年时全球有18%的中产阶级住在北美，另有36%在欧洲，亚洲（计入日本）为28%。