January 20, 2023
EITC: Updated District and Locality Data — Methodology Note
Detailed Methodology
These tables are based on zip- and locality-level IRS Statistics of Income (SOI) data for tax year 2020.
https://www.irs.gov/statistics/soi-tax-stats-individual-income-tax-statistics-2020-zip-code-data-soi
District-level estimates were generated by crosswalking the IRS SOI zip data to 2010 Census blocks using the geographic correspondence engine from the Missouri Census Data Center at the University of Missouri, which generates weighting factors to convert zip-level data to 2010 block-level data.
https://mcdc.missouri.edu/applications/geocorr2018.html
The 2010 block-level data were converted to 2020 block-level data using the IPUMS National Historical Geographic Information System (NHGIS) block crosswalks (see IPUMS NHGIS, University of Minnesota, www.nhgis.org)
The 2020 blocks were then assigned to Virginia House and Senate districts using the block assignment file from the Supreme Court of Virginia special masters’ materials.
Acknowledgments
We thank Claire Zippel of the Center on Budget and Policy Priorities for helpful suggestions and technical assistance.
