A recent earnings report from Delta offers yet another illustration. While Delta's main cabin revenue fell 5% for the June quarter compared to a year ago, premium ticket sales rose 5%, highlighting the divide between affluent customers and those forced to be more economical.Josephson and other economists say the shrinking traffic of low-income consumers is emblematic of a larger trend of Americans diverging in their spending, with wealthier customers flexing their purchasing power and lower-income shoppers ...