This story is a collaboration between the Illinois Answers Project and the Chicago Tribune .

Chicago homeowners are being walloped with a record property tax hike, with some of the city’s poorest neighborhoods absorbing the steepest increases even as downtown office owners see their bills fall, according to new data from the Cook County treasurer’s office.

An analysis from Cook County Treasurer Maria Pappas’ office found the median property tax bill for a Chicago homeowner jumped 16.7% since last year, the largest percentage increase in at least 30 years. The surge follows similar spikes in Cook County’s north and south suburbs over the last two years and complicates the job of the Chicago City Council as it considers tax hikes to help close a historic budget gap.

The long-a

See Full Page