Illinois Answers and the Chicago Tribune looked at property assessments across Cook County. Here's what we found.

Fritz Kaegi's office missed new construction, classifying new buildings as vacant lots, among other oversights. The result in 2023 alone was more than $440 million in untaxed property value across 36 of the county's 38 townships.

Hover over each township to see how many properties, and how much taxable value, was missed in each area.

Illinois Answers and the Chicago Tribune looked at thousands of properties that were built or renovated since 2017 to see whether the Cook County Assessor's Office factored the changes into assessments. For the 620 properties determined to be improperly assessed, the analysis compared the value of each parcel's most recent sale to the assessor's first 2023 valuation. The difference between the two numbers for each property is its "missing value."
Chart: Cam RodriguezSource: Illinois Answers and Chicago Tribune analysis; Cook County Assessor's OfficeGet the dataCreated with Datawrapper