Working Paper
Lost in Aggregation: Geographic Mismeasurement of Income and Spending
Abstract: Using zip-code median income as a proxy for household income is common in economics but can mask heterogeneity and yield misleading conclusions. Using zip-code median income and self-reported household incomes from a representative panel of 150,000 U.S. households, we decompose average retail spending for 2018-2024. When using self-reported incomes, we observe substantial divergence in spending between low- and high-income households starting in mid-2021. When using zip-code aggregates as a proxy, this divergence disappears. Our findings indicate a 35 to 75 percent discrepancy between zip-code aggregates and self-reported incomes, highlighting the limitation of zip-code aggregates as a proxy for household incomes.
JEL Classification: E01; E20; E32;
https://doi.org/10.17016/FEDS.2025.050
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File(s): File format is application/pdf https://www.federalreserve.gov/econres/feds/files/2025050pap.pdf
Bibliographic Information
Provider: Board of Governors of the Federal Reserve System (U.S.)
Part of Series: Finance and Economics Discussion Series
Publication Date: 2025-07-07
Number: 2025-050