Robert Frank, an economist at Cornell University, for instance, found that in counties with the widest income gaps, rates of personal bankruptcy and divorce rates were higher than average. He also notes that when wealthier families see their incomes rise at a faster pace than everyone else, their spending can create what he calls an "expenditure cascade." That is, the demand for bigger and better homes or safer cars can create new standards for those lower down on the economic scale.
New report looks at where the growth in incomes of high-income families has outpaced that of middle- and low-income households.
