US income inequality is largely a consequence of the numbers of earners in each household. Top 1/5 of households have 2.06 earners while bottom 1/5 has 0.4 earners. Income inequality decreases from 18x higher to 3.6x if you account for this discrepancy.
"Married-couple households represent a much greater share of the top income quintile (76.1%) than for the bottom income quintile (17.1%), and single-parent or single households represented a much greater share of the bottom one-fifth of households (82.9%)"
US income inequality is largely a consequence of the numbers of earners in each household. Top 20% of households have 2.06 earners while bottom 20% has 0.4 earners. Income inequality decreases from 18 times to 3.6 times if you account for this.