Income Inequality.

Income inequality in the United States remained relatively stable for a period of nearly forty years. Beginning in the 1970's, however, this period of stability ended, as the first signs of widening income inequality became apparent. Over the course of the 1970's and 1980's, an increasingly clear trend toward greater income inequality emerged. By the end of the 1980's, the top 20 percent of workers were receiving the largest share of income ever recorded by government …

…have taken place that tends to provoke differences in household incomes. For example, divorces and separations, births out of wedlock, and the increasing age at first marriage have led to a shift away from married-couple households and toward single-parent and non-family households, which typically have lower incomes. Also, the increasing tendency over the period for men with higher-than-average earnings to marry women with higher-than-average earnings has contributed to widening gap between high-income and low-income households.