Is rising geographic income inequality driven by concentrated affluence?
Core argument: The rise in U.S. geographic inequality is driven primarily by the concentration of affluence, with top income quantiles diverging significantly across states since the late 1970s while median household incomes across counties show only gradual dispersion.
The rise in American geographic inequality is primarily driven by the concentration of affluence, with top income quantiles diverging significantly across states since the late 1970s. While median household incomes have shown a gradual increase in dispersion across counties, the divergence in top income quantiles has been more pronounced. In contrast, poverty rates and bottom income quantiles have converged across areas, reflecting a democratization of poverty. This convergence is supported by the equalization of poverty rates and means-tested transfers across locations, indicating that geographic inequality is not primarily due to the migration of less educated workers. The dispersion in county-level fortunes, particularly in the West and Northeast, underscores the growing spatial inequality driven by affluent households.











Ed Comment, “What is the difference between graph a and c, and graphs b and d? The paper seems to say the super-rich have moved to the coasts while everyone else is converging.”
The convergence in poverty rates, “….First, poverty rates have equalized both within and between Census regions (Figure A.2). The between region component has played a dominant role in this equalization post-2000 as poverty rates rose in the Northeast and Midwest relative to the South and West(Figure A.3). Second, counties that were very poor in 1990 had large reductions in poverty by 2018, while those that were less poor had substantial poverty increases (Figure A.4). Finally, the poverty dissimilarity index also fell dramatically between the 1960 and 1980 Censuses (Figure A.5)….”
Key findings, “…..Our findings paint a more nuanced story than the common refrain that American communities are growing apart. Mean incomes are diverging across areas but those means give outsize influence to individuals with especially high incomes. In contrast, median incomes, which arguably provide a better measure of the well-being of a typical household, exhibit more muted divergence over the past thirty years. The equalization of poverty rates across space we document aligns closely with independent evidence that bottom income percentiles and means-tested transfers are converging across locations. Given that the migration flows of less educated workers are only weakly related to area income (Ganong and Shoag, 2017), we suspect this democratization of poverty is not driven primarily by a reshuffling of households. An interesting question for future research is the extent to which changes in labor market institutions such as the minimum wage or transfer programs such as disability insurance are driving these trends. The increasing geographic concentration of high income households we document is broadly consistent with the well known rise in top incomes across individuals. Perhaps influenced by these trends, coastal states including New York and California have recently enacted or increased “millionaire taxes” on households with high incomes. Assessing whether place based millionaire taxes will be subverted by income shifting or real migration responses is a priority for future research….”
Steve Comment: “So in Figure 3 the left two Figures (A,C) are pre-tax income, the right two figures (B,D) are pre-tax income including transfers. They are using them to prove your takeaway, the increase took place in the Middle Atlantic, Pacific, and New England Census divisions driven by high earners disproportionately relocating there. Here is how they describe Figure 3, “The upper panels of Figure 3 display estimates of dispersion within Census regions along with the between region component of variance. Between region income inequality has remained remarkably stable over the past 40 years. In contrast, dispersion across counties in the West and Northeast has risen dramatically. The lower panels of Figure 3 reveal that much of this increase took place in the Middle Atlantic, Pacific, and New England Census divisions. Cross-division inequality has remained remarkably stable, indicating that inequality patterns are not driven by coastal states drifting apart from inland communities. Rather, dispersion in the fortunes of counties within these states is driving the steady increase in county level inequality…”…”