Household income in the United States
Household type is strongly correlated with household income. Married couples are disproportionately represented in the upper two quintiles, compared to the general population of households. Cross-referencing shows that this is likely due to the presence of multiple income earners in these families. Non-family households (individuals) are disproportionately represented in the lower two quintiles. Households headed by single males are disproportionately found in the middle three quintles; single females head households concentrated in the bottom three quintiles.