Assessor’s Office releases improved residential assessment model used for 2018 Triennial Reassessment of City of Chicago

8/2/2018, 11:26 a.m. | Updated on 8/2/2018, 11:26 a.m.

Assessor’s Office releases improved residential assessment model used for 2018 Triennial Reassessment of City of Chicago

Indicators of accuracy meet or exceed industry standards for minimal regression

Cook County Assessor Joseph Berrios announced today that his office is releasing the improved residential regression model used for the current 2018 reassessment of the City of Chicago.

Assessor Berrios said, “Improving residential assessments has been a top priority and with the new resources now available to us from Civic Consulting Alliance (CCA) and Tyler Technologies (“Tyler”), we have been able to accomplish what we set out to do.”

Berrios added, importantly, “Our office is not only releasing our improved regression model but is also providing email exchanges between experts of Tyler, CCA and the Cook County Assessor’s Office (CCAO). We are also disclosing methodology reports, in order to be as transparent as possible.” Release of the model and other material makes them available upon request.

Reflective of the collaboration now in its second year, CCAO worked with CCA and Tyler to assemble and release the model and related information. In June 2017, Berrios pledged to work with CCA and Tyler to improve residential assessment modeling and related processes. Work with Tyler actually began years ago; it shows in lower and better Coefficient of Dispersion (COD; measures regressivity) performance statistics for the 2018 City of Chicago reassessment.

Lakeview and Rogers Park Township have CODs which are better than industry standards and are 12.950 and 12.641, respectively. Based on Illinois Department of Revenue statistics, Hyde Park Township has had an over 20-point reduction in its COD, compared to the last triennial reassessment.

“I thank County Board President Toni Preckwinkle for her help with the Tyler Technologies contract, CCA for its very important role, CCA expert Josh Myers, Tyler-affiliated expert Dr. Richard Borst and Tyler for its overall fine work,” Assessor Berrios added.

He concluded, “Everyone in the Assessor’s Office also worked diligently to meet the goal of developing a better model and improving the assessment process. We have never wavered from our commitment to reducing regressivity and assessing property as accurately and fairly as possible.”

CCAO reassesses one-third of the more than 1.8 million parcels of Cook County property each year. The Tax Year 2018 Triennial Reassessment is of all properties located in the eight Chicago townships. Our work with these experts,, to produce the new model took place while reassessing the entire City - the largest and most diverse reassessment district in the County.

Reassessment notices contain proposed property values for Tax Year 2018, which will be reflected on Second-Installment Tax Bills to be mailed and due in the summer of 2019.