Assessor's Office Honored with National Association of Counties Achievement Award

Tuesday, July 11, 2023

News Social Media

Cook County- The Cook County Assessor’s Office (CCAO) received a National Association of Counties Achievement Award for the creation of a tool called the Property Tax Simulator, also known as PTAXSIM. This is a software code package implemented in the coding language R and is designed to recalculate changes to Cook County property tax bills. It uses real assessment, exemption, TIF, and levy data to generate historic, line-by-line tax bills for properties in Cook County from tax years 2006 to 2020. Why is this important? Policy makers, researchers, and journalists can now create historical counterfactual scenarios to determine how policy changes could impact the property tax system.

 “This award is a testament to our continued commitment to using modern tools to build transparency, trust, and educate stakeholders throughout the County,” said Assessor Fritz Kaegi. “Researchers and policymakers can use PTAXSIM to analyze the whole system of appeals, exemptions, and tax levies – an unprecedented resource for academics, journalists, and policymakers.”

Since its publication, PTAXSIM has been featured in a recorded talk for civic tech enthusiasts, received public suggestions for added data, used to produce five counterfactual analyses, and is currently in use by external policy researchers. The public can watch PTAXSIM in action on our YouTube channel.

PTAXSIM is an R package that can be downloaded here: The CCAO Data Department welcomes questions at 

For more information and to view the complete list of award winners, visit