Bells in Space: The Spatial Dynamics of US Interpersonal and Interregional Income Inequality

Social and interregional inequality patterns across US states from 1929-2012 are analyzed using exploratory space-time methods. The results suggest complex spatial dynamics for both inequality series that were not captured by the stylized model of Alonso (1980). Interpersonal income inequalities of states displayed a U-shaped pattern ending the period at levels that exceeded the alarmingly high patterns that existed in the 1920s. Social inequality is characterized by greater mobility than that found for state per capita incomes. Spatial dependence is also distinct between the two series, with per capita incomes exhibiting strong global spatial autocorrelation, while state interpersonal income inequality does not. Local hot and cold spots are found for the per capita income series, while local spatial outliers are found for state interpersonal inequality. Mobility in both inequality series is found to be influenced by the local spatial context of a state.