Trends in Income Inequality, Volatility and Mobility Risk

There has been a renewed interest in recent years in income inequality, economic mobility, and income volatility. I define an aggregate measure of income risk as half the squared coefficient of variation of incomes measured over both people and time, which can be decomposed into an inequality component measuring dispersion in mean incomes, a volatility component measuring the average dispersion of fluctuations about person-specific trends, and a mobility component measuring the dispersion of person-specific trends. I apply this decomposition to the Panel Study of Income Dynamics to characterize trends in inequality, volatility, and mobility over the last several decades in the United States. I also examine changes in the regressivity of income growth over time.