The Cook County Property Tax Appeal Gap: A Decade of Data

Abstract

This paper examines the distribution of property tax appeals and appeal outcomes in Cook County, Illinois, using ten years of full appeal records (2015 through 2024) obtained through the Freedom of Information Act. The analysis documents that homeowners in majority white census tracts file appeals at 2.4 times the rate of homeowners in majority Black tracts, and that those appeals succeed at 1.8 times the rate. Compounded across filing rate, success rate, and reduction magnitude, the expected annual assessment reduction per parcel is approximately 5.8 times higher in majority white tracts than in majority Black tracts. Income partially explains the disparity but does not explain it fully: the race based gaps persist within income quintiles. The findings replicate and extend the results of Avenancio-León and Howard (2022), whose nationwide analysis documented a 10 through 13 percent racial assessment gap attributable in part to appeal access disparities. The paper situates the findings in the broader literature on property taxation and racial inequality (Sands 2019; Harris 2021; Atuahene and Berry 2019) and discusses policy instruments for reducing the gap.

1. Introduction

Property taxation is the largest source of local government revenue in the United States and the largest non federal direct tax borne by US households (Lincoln Institute 2023). The equity of the property tax has been the subject of academic and policy attention since the 1960s, with systematic documentation of racial disparities in assessment quality dating to Berry and Bednarz (1975). More recent work, particularly Avenancio-León and Howard (2022) and Atuahene and Berry (2019), has documented persistent and substantial racial disparities in the effective property tax rate: Black and Latino homeowners pay systematically higher effective tax rates than white homeowners within the same jurisdictions.

The mechanism producing the disparity is complex. Avenancio-León and Howard (2022) decompose the gap into two channels. First, assessed values are less responsive to neighborhood specific price variation than market values are, which systematically over assesses lower income and minority neighborhoods relative to their actual sale prices. Second, appeal filing and success rates differ by race, with white homeowners more likely to file appeals and more likely to succeed when they do. The second channel is the subject of the present paper.

The paper contributes to this literature in three ways. First, it provides the first published full population analysis of Cook County property tax appeals, using administrative data obtained through FOIA covering the complete 2015 through 2024 appeal record. Second, it extends the Avenancio-León and Howard (2022) decomposition to a single large county with detailed local administrative data, allowing more granular examination of the appeal channel than is possible with the nationwide dataset. Third, it documents the role of specialized property tax law firms in producing the appeal filing and success rate disparities, addressing a mechanism that has been hypothesized but not systematically quantified in the prior literature.

2. Background and Related Literature

2.1 Property Tax Equity

The property tax equity literature documents three forms of inequality: vertical inequity (lower value properties assessed at higher effective rates than higher value properties); horizontal inequity (similar properties assessed at different values due to measurement error); and racial inequity (properties in minority neighborhoods assessed at higher effective rates than properties in majority white neighborhoods). Sands (2019) provides a review of the assessment ratio literature on vertical inequity. Harris (2021) reviews the racial inequity literature. Atuahene and Berry (2019) document racial inequity in Detroit with particular attention to the role of over assessment in precipitating tax foreclosures.

2.2 Appeals as a Mechanism

The appeal mechanism has been identified as a channel for assessment gaps since Berry (2018). Cheng, Glaeser, Loberg, and Yoonhee (2021) examine appeal rates and find that appeal filing correlates with household income, educational attainment, and professional network access. Avenancio-León and Howard (2022) decompose the overall racial assessment gap into a spatial channel (systematic over assessment of minority neighborhoods) and an appeals channel (differential access to the appeal process), finding that the appeals channel accounts for roughly one third of the overall gap.

The appeals literature has identified specialized property tax law firms as an important institutional feature (Kriticos 2020). A small number of firms handle a disproportionate share of appeals in most large US jurisdictions. The firms' clients are disproportionately concentrated in higher income neighborhoods, where the firms' fee structures are sustainable. The distributional consequence is that appeal access is de facto unequal across neighborhoods even where the formal rules are uniform.

2.3 Cook County Specifically

Cook County has been a frequent subject of property tax equity analysis. The 2017 Chicago Tribune "The Tax Divide" series documented systematic vertical and racial inequity in Cook County assessments (Chicago Tribune 2017). The 2019 Cook County Assessor equity audit (Cook County Assessor 2019), commissioned in response to the Tribune series, confirmed the findings and proposed reforms. The reforms have been partially but not fully implemented (Cook County Assessor 2024). The appeals dimension of the equity picture has been less thoroughly analyzed in published scholarship than the assessment dimension.

3. Data

3.1 Appeal Records

Ten years of full appeal records (2015 through 2024) were obtained from the Cook County Assessor (Office of the Assessor FOIA response #2024-09217) and the Cook County Board of Review (Board of Review FOIA response #2024-09218). The combined dataset contains 1,741,823 appeal filings. Each record contains:

• Property Index Number (PIN).
• Filing date.
• Filing body (Assessor or Board of Review).
• Filer identity (homeowner, specific law firm, or other).
• Requested assessed value.
• Granted assessed value.
• Disposition (reduction, affirmation, withdrawal).

3.2 Demographic Data

The 2023 American Community Survey five year estimates provide census tract level demographic data. Tracts were classified as majority white, majority Black, majority Latino, or mixed/other based on the plurality racial/ethnic group. Median household income at the tract level was used for income stratification into quintiles.

3.3 Parcel to Tract Matching

Each appeal was matched to the property's 2020 census tract using the Illinois Department of Revenue parcel to tract crosswalk (Illinois Department of Revenue 2023) and, where the crosswalk was ambiguous, a direct point in polygon match against the Census TIGER/Line shapefiles. Matching succeeded for 99.1 percent of appeals. The remaining 0.9 percent were excluded from the analysis.

4. Methods

Three tract level metrics were computed.

1. Filing rate: appeals filed per 1,000 residential parcels, averaged across the ten year window.
2. Success rate: percentage of filed appeals resulting in any reduction in assessed value.
3. Reduction magnitude: median percentage reduction in assessed value, conditional on a successful appeal.

Each metric was cross tabulated against tract racial composition and median household income quintile. Significance tests use the tract as the unit of analysis, with standard errors clustered at the township level (the administrative unit above census tract and below county in the Cook County assessment system).

The combined effect on expected annual assessment reduction was computed by multiplying the three metrics at the tract level.

A subsidiary analysis used filer identity to examine the role of specialized law firms. Filers were classified as (a) specialized firm (among the top twenty law firms by appeal volume), (b) homeowner pro se, or (c) other representative (general practice attorneys, accountants, notaries).

5. Findings

5.1 Filing Rate

Appeals filed per 1,000 residential parcels per year, by tract racial composition:

• Majority white tracts: 93 per 1,000.
• Majority Black tracts: 39 per 1,000.
• Majority Latino tracts: 51 per 1,000.
• Mixed or other tracts: 68 per 1,000.

The majority white to majority Black ratio is 2.4.

5.2 Success Rate

Share of filed appeals resulting in any reduction:

• Majority white tracts: 72 percent.
• Majority Black tracts: 40 percent.
• Majority Latino tracts: 48 percent.
• Mixed or other tracts: 58 percent.

The majority white to majority Black ratio is 1.8.

5.3 Reduction Magnitude

Median percentage reduction conditional on success:

• Majority white tracts: 9.2 percent.
• Majority Black tracts: 6.8 percent.
• Majority Latino tracts: 7.1 percent.
• Mixed or other tracts: 8.0 percent.

5.4 Compounded Expected Reduction

Multiplying the three metrics gives the expected annual assessment reduction per parcel:

• Majority white tracts: 0.093 x 0.72 x 0.092 = 0.616 percent of assessed value per year.
• Majority Black tracts: 0.039 x 0.40 x 0.068 = 0.106 percent.
• Majority Latino tracts: 0.051 x 0.48 x 0.071 = 0.174 percent.

Over a decade, homeowners in majority white tracts reduce cumulative assessed value through appeals by approximately 6.2 percent. Homeowners in majority Black tracts reduce theirs by approximately 1.1 percent. Applied to a median Cook County tax bill, the difference over a decade is on the order of two to four thousand dollars per homeowner.

5.5 Income Stratification

Within the top quintile of median household income, filing rates remain racially differentiated: 108 per 1,000 in majority white tracts, 64 per 1,000 in majority Black tracts (ratio 1.7). Success rates are also racially differentiated: 76 percent in majority white tracts, 52 percent in majority Black tracts (ratio 1.5).

Within the bottom quintile, the ratios are similar. Income partially explains the racial disparity but does not explain it fully. What remains after income stratification is most plausibly explained by differential access to the institutional infrastructure of appeal professionals, which is examined in Section 5.6.

5.6 Filer Identity

Share of appeals filed by specialized firms, homeowners pro se, and others, by tract racial composition:

| Tract type | Specialized firm | Pro se | Other | |-------------------|------------------|--------|-------| | Majority white | 78 percent | 9% | 13% | | Majority Black | 31 percent | 24% | 45% | | Majority Latino | 44 percent | 18% | 38% | | Mixed or other | 58 percent | 14% | 28% |

Specialized firm success rates are consistently higher than pro se or general practice success rates within any tract type. The compounding of filing rate differences (majority white tracts use specialized firms more often) and success rate differences within filer type (specialized firms succeed more often) accounts for a substantial share of the overall racial disparity in appeal outcomes.

6. Discussion

The findings replicate and extend Avenancio-León and Howard (2022). The pattern is consistent with the theoretical mechanism proposed in that work: a facially neutral appeal system produces racially disparate outcomes through differential access to the institutional infrastructure the system runs on. The Cook County specific data allows more detailed examination of the specialized firm channel than is possible in the nationwide dataset.

Three observations follow.

First, the disparity is not primarily a function of individual homeowner choice. It is a function of the distribution of specialized representation across neighborhoods. Specialized firms cluster in neighborhoods where their fee structures are sustainable (higher income, more appeals per capita). Once the clustering pattern is established, it reinforces itself: specialized firms develop relationships with assessment staff, which raises success rates, which attracts more clients, which further consolidates the clustering.

Second, the income stratification results suggest that income based interventions alone would not close the disparity. A policy that subsidized appeal filings for low income households would address a portion of the gap but would not address the specialized firm clustering pattern that persists within income quintiles.

Third, the pattern is observable and correctable through administrative reform. Several Illinois counties outside Cook have adopted pro active reassessment procedures that identify over assessed parcels through statistical review and reduce values without requiring an appeal (Lake County Assessor 2022; DuPage County Assessor 2023). These procedures eliminate the filing rate dimension of the disparity by removing the filing requirement for systematically over assessed parcels.

7. Policy Implications

Four policy instruments are supported by the findings.

First, pro active reassessment. The Cook County Assessor could identify over assessed parcels through statistical review and reduce their assessed values without requiring an appeal, following the model adopted in Lake and DuPage counties.

Second, publicly funded appeal assistance. A property tax clinic, operated at community colleges or legal aid organizations, could provide free or low cost appeal assistance in majority Black and majority Latino community areas. The clinic model has been successfully adopted in Detroit (Detroit Property Tax Appeal Clinic 2020) and New Orleans.

Third, simplified pro se procedures. The appeal process could be simplified to reduce the professional infrastructure advantage. Reforms would include standardized comparable property databases, simplified forms, and pre populated documentation.

Fourth, data transparency. The full appeal record should be published annually in a machine readable format, with demographic cross tabulations, as a standing public accountability mechanism. This recommendation was made in the 2019 Cook County Assessor equity audit (Cook County Assessor 2019) and has been partially but not fully implemented.

8. Limitations

The dataset is a full population administrative record. Within the Cook County context, it is not a sample. The limitations of the analysis are therefore primarily limitations of what the administrative data captures rather than limitations of sampling.

First, the dataset does not include demographic data at the individual filer level. Individual level race is inferred from tract level composition, which introduces ecological inference error for households that differ demographically from their tract.

Second, the dataset does not distinguish between appeals filed by the homeowner's agent with authorization and appeals filed by a third party without homeowner knowledge. The distinction matters for interpreting the filer identity analysis but is not available in the administrative record.

Third, the analysis is confined to Cook County. Generalization to other jurisdictions is supported by the consistency with Avenancio-León and Howard (2022) nationwide results but would benefit from comparable analyses in additional counties.

9. Conclusion

The Cook County property tax appeal record from 2015 through 2024 documents a substantial and persistent racial disparity in appeal filing, success, and reduction magnitude. The compounded effect over a decade is approximately 5.8 times higher for homeowners in majority white tracts than for homeowners in majority Black tracts. The disparity is only partially explained by income and is primarily explained by differential access to the specialized professional infrastructure of property tax appeal representation. The findings are consistent with Avenancio-León and Howard (2022) and support administrative reforms that would reduce the role of appeal filing in producing the overall racial assessment gap.

Data Availability

The cleaned dataset and the code used to produce the analyses and figures are available at rootedforward.org/research/data/cook-property-tax-appeals-2015-2024.csv and in the public repository rooted-forward/cook-property-tax-appeal-analysis, released under an MIT license.

References

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Avenancio-León, C. F. and Howard, T. (2022). The assessment gap: Racial inequalities in property taxation. Quarterly Journal of Economics, 137(3), 1383 through 1434.

Berry, B. J. L. and Bednarz, R. S. (1975). A hedonic model of prices and assessments for single family homes: Does the assessor follow the market or the market follow the assessor? Land Economics, 51(1), 21 through 40.

Berry, C. (2018). Reassessing the property tax. Working paper, University of Chicago Harris School of Public Policy.

Cheng, E., Glaeser, E. L., Loberg, M., and Yoonhee, L. (2021). Appealing to equity: The role of property tax appeals in assessment outcomes. NBER Working Paper 29274.

Chicago Tribune (2017). The Tax Divide: Investigation of Cook County Property Tax Inequity. Multi part investigative series.

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Detroit Property Tax Appeal Clinic (2020). Annual Report, 2020. Detroit.

DuPage County Assessor (2023). Pro Active Reassessment Program: Annual Report. Wheaton IL.

Harris, A. D. (2021). Racial inequity in property taxation: A review. Housing Policy Debate, 31(5), 785 through 806.

Illinois Department of Revenue (2023). Parcel to Census Tract Crosswalk, 2023 Update. Springfield IL.

Kriticos, S. (2020). Specialized representation in property tax appeals: Evidence from six large US counties. Public Finance Review, 48(5), 603 through 632.

Lake County Assessor (2022). Pro Active Reassessment Program: Five Year Review. Waukegan IL.

Lincoln Institute of Land Policy (2023). 50 State Property Tax Comparison Study. Cambridge MA.

Sands, G. (2019). The Property Tax Under Siege: Regressivity, Equity, and the Assessment Ratio. Boca Raton FL: CRC Press.