Income

About

The Income dimension is constructed using three indicators: the Median Household Income Gap, the Unemployment Gap, and the Below-poverty Gap, which capture racial disparities in economic resources, employment opportunities, and poverty across places.

Why is the Income Important to the Structural Racism and Discrimination (SRD) Index?

Income inequality is a core pathway through which structural racism and discrimination shape racial and socioeconomic disadvantage1,2,3,4. Historical and ongoing labor market discrimination, unequal access to educational and economic opportunities, and racially stratified employment systems have contributed to persistent income gaps between Black and White households5,6,7. These disparities limit economic security and constrain access to resources that are essential for health, stability, and upward mobility2,6.

Income inequality also reinforces and interacts with other dimensions of structural racism captured in the SRD Index. Lower household incomes, higher unemployment rates, and elevated poverty levels are closely linked to residential segregation, housing instability, reduced access to quality education and healthcare, and increased exposure to environmental and social risks8,9. As a result, income serves as a foundational mechanism through which economic disadvantage becomes spatially concentrated and reproduced across generations.

How is the Income Calculated?

The Income dimension is calculated using three indicators: Median Household Income Gap, Unemployment Gap and Below-poverty Gap. Each indicator is first computed as an income gap measure and then standardized to ensure comparability across counties.

STEP 1: Indicator standardization

The median household income gap, unemployment gap, and below-poverty gap indicators are converted into Z scores after adjusting for outliers using top and bottom coding, following the SRD Index methodology.

STEP 2: Reversing the Z-Scores

The Z-scores for all indicators were not reversed. A higher Z-scores for the median household income gap, unemployment gap, and below-poverty gap contributes to a higher value or score of the SRD index.

STEP 3: Dimension score calculation

The Income Z score is calculated by taking the average of the three indicator Z scores:

Income Z score = (Z5 + Z6 + Z7) / 3

where Z5 represents median household income gap, Z6 represents unemployment gap and Z7 represents below-poverty gap

STEP 4: Ranking

The Income Z scores are then converted into rank scores, where a higher score indicates a greater impact of racism and discrimination within this dimension.

References

  1. Egede, L. E., Walker, R. J., & Williams, J. S. (2024). Addressing structural inequalities, structural racism, and social determinants of health: a vision for the future. Journal of General Internal Medicine, 39(3), 487-491.
  2. Williams, D. R. (1999). Race, socioeconomic status, and health the added effects of racism and discrimination. Annals of the New York Academy of Sciences, 896(1), 173-188.
  3. Phelan, J. C., & Link, B. G. (2015). Is racism a fundamental cause of inequalities in health?. Annual Review of Sociology, 41(1), 311-330.
  4. Nazroo, J. Y. (2003). The structuring of ethnic inequalities in health: economic position, racial discrimination, and racism. American journal of public health, 93(2), 277-284.
  5. Massey, D. S. (2007). Categorically unequal: The American stratification system. Russell Sage Foundation.
  6. Bloome, D. (2014). Racial inequality trends and the intergenerational persistence of income and family structure. American sociological review, 79(6), 1196-1225.
  7. Manduca, R. (2018). Income inequality and the persistence of racial economic disparities. Sociological Science, 5, 182-205.
  8. Wolfe, A. (2011). Economic Racism: A Look at the Black-White Income Gap, 1967-2001. McNair Scholars Research Journal, 7(1), 18.
  9. O’Brien, R., Neman, T., Seltzer, N., Evans, L., & Venkataramani, A. (2020). Structural racism, economic opportunity and racial health disparities: evidence from US counties. SSM-Population health, 11, 100564.