The Structure of American Income Inequality*

Income inequality is examined using the Panel Study of Income Dynamics and a consistent decomposition analysis. I only use inequality measures that satisfy the Principle of Transfers, have the property that a ceteris paribus increase in inequality within any subgroup increases overall inequality, and are independent of the scale of income and population. Decompositions are carried out by family size and by age of head for several definitions of income and income recipient. Whilst changing the time unit over which income is measured has a substantial impact on inequality, the effect of removing the between‐age‐group component of inequality is relatively slight.