Now a pink slip, a bad diagnosis, or a disappearing spouse can reduce a family from solidly middle class to newly poor in a few months.

• 如今，一份解雇通知书、一张疾病诊断书或者配偶的去世都可能在几个月之内从一个收入殷实的中产阶层家庭跌为一个新贫民阶层。