💰 Property Tax — ProPublica / Cook County Analysis
Poor Properties Taxed at 3× the Rate of Rich Ones
In Chicago's Cook County, the poorest properties face effective tax rates 3 times higher than the most expensive homes. The tax system is upside down — by design.
3×Higher effective tax rate for cheap vs expensive properties in Cook County
$2.2BOvertaxation of low-value properties in IL since 2000 (est.)
44US states with documented regressive property tax patterns
1.8%Avg effective rate for bottom-quintile vs 0.6% for top-quintile
Choose your depth. The data doesn't change — just the explanation.
Property taxes should be fair — you pay a set percentage of what your home is worth. But in Chicago, if your home is cheap, you're actually paying 3 times the percentage that rich homeowners pay. A $100,000 house might be taxed at 1.8%, but a $1,000,000 mansion is taxed at 0.6%. This happens because cheap homes are overvalued by assessors, and expensive homes are undervalued.
Property taxes are calculated as: assessed value × tax rate. The "effective tax rate" is what you actually pay as a percent of market value. In Cook County, the assessor's office historically overassessed cheap properties (often in Black and Latino neighborhoods) and underassessed expensive ones. ProPublica's 2017 investigation proved this with comprehensive sales data. The result: poor homeowners pay 3× more as a share of their home's value — a massive upside-down tax.
ProPublica/Chicago Tribune (2017) matched Cook County Assessor records against actual sales prices to calculate assessment-sales ratios by property value quintile. Result: bottom quintile assessment ratio = 3.2× top quintile. This violates Illinois law (uniform assessment requirement) and the 14th Amendment's equal protection clause. Lincoln Institute of Land Policy (2022) found similar regressive patterns in 44 of 50 states. Key mechanism: mass appraisal models using comparable sales systematically undervalue luxury properties (fewer comps, less market transparency) and overvalue low-end properties (more sales, easier regression anchor). Cook County reform under Fritz Kaegi (elected 2018): assessment equity improved but gap persists.
ProPublica analysis: propublica.org/series/the-tax-divide (2017). Cook County Assessor open data: cookcountyassessor.com/data-portal. Assessment ratio studies: Lincoln Institute of Land Policy "50-State Property Tax Comparison" (2022). Illinois PTELL (Property Tax Extension Limitation Law) data. IAAO Standard on Ratio Studies for methodology. Kaegi reform progress: cookcountyassessor.com/data-portal/assessor-data/residential-assessments. Illinois Dept of Revenue assessment equity data.
Cook County — The Anatomy of a Regressive Tax
The cheaper your home, the more you pay as a share of its value. This is legal in most states, documented across the country, and almost never discussed.
Effective Property Tax Rate by Property Value Quintile (Cook County)
What % of actual market value homeowners pay in property taxes — by property price tier
Effective rate differential (low-value vs high-value homes) in major US metros
This Is a Transfer of Wealth — Upward
The regressive property tax is a quiet, legal mechanism that transfers wealth from poor homeowners to the government at a higher rate than from rich ones — then uses that same tax revenue to fund schools and services that disproportionately benefit wealthier areas. The system extracts from the bottom and invests in the top.
Sources
ProPublica / Chicago Tribune "The Tax Divide" Investigation (2017) · Lincoln Institute of Land Policy, 50-State Property Tax Comparison (2022) · Cook County Assessor Open Data Portal · Illinois Dept of Revenue Assessment Equity Data · IAAO Standard on Ratio Studies