A Ninety-Year Panel of Annual U.S. State-Level Income Inequality Measures

This paper introduces a new panel of annual state-level income inequality measures over the ninety year period 1916-2005.  Among many of the states inequality followed a U-shaped pattern over the past century, peaking both before the Great Depression and again at the time of the new millennium.  The new panel reveals significant state-level variations, both before the year 1945, and regionally.  While Northeastern states are strongly correlated with aggregate U.S. trends, we find many of the Western states have little overall correlation over the past century.  The availability of this new panel may prove useful to empirical researchers interested in all aspects of income inequality, particularly given the panel’s unusually large number of both time-series and cross-sectional observations.