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@ccao-data

Cook County Assessor's Office

The CCAO's Data Department creates models, tools, and analyses to improve Cook County's property tax system

Hi there! 👋

We're the Cook County Assessor's Data Department. We make predictive models to help determine the assessed value of every residential and condominium property in Cook County. We also make tools and reports to make the Cook County property system more transparent, predictable, and fair.

Our work

Our tiny team has done some big work since 2018. Here are some of the things we're most proud of:

Get involved

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  1. model-res-avm Public

    Automated valuation model for all class 200 residential properties in Cook County (except vacant land and condos)

    R 42 8

  2. data-architecture Public

    Codebase for CCAO data infrastructure construction and management

    R 6 4

  3. model-condo-avm Public

    Automated valuation model for all class 299 and 399 residential condominiums in Cook County

    R 10 4

  4. ptaxsim Public

    R package for estimating Cook County property tax bills

    R 16 3

  5. model-sales-val Public

    Heuristics for detecting outlier and non-arms-length sales

    Python 2 1

  6. wiki Public

    Handbook, how-tos, and other documentation

    HTML 4 1

Repositories

Showing 10 of 27 repositories
  • data-architecture Public

    Codebase for CCAO data infrastructure construction and management

    R 6 4 76 9 Updated Apr 17, 2025
  • extract-permits Public

    Script and workflow for permit data extraction

    Python 0 0 3 0 Updated Apr 15, 2025
  • model-res-avm Public

    Automated valuation model for all class 200 residential properties in Cook County (except vacant land and condos)

    R 42 AGPL-3.0 8 25 2 Updated Apr 15, 2025
  • wiki Public

    Handbook, how-tos, and other documentation

    HTML 4 1 12 0 Updated Apr 11, 2025
  • public Public

    Entrypoint for public engagement with the CCAO Data Department

    R 0 0 3 0 Updated Apr 11, 2025
  • ptaxsim Public

    R package for estimating Cook County property tax bills

    R 16 AGPL-3.0 3 18 1 Updated Apr 4, 2025
  • lightsnip Public

    Hard fork of curso-r/treesnip specifically for CCAO LightGBM regressions

    R 2 AGPL-3.0 0 2 1 Updated Mar 10, 2025
  • assessr Public

    R package for measuring assessment performance

    R 6 AGPL-3.0 2 1 1 Updated Mar 10, 2025
  • ccao Public

    R package of functions and datasets used throughout the CCAO assessment pipeline

    R 1 AGPL-3.0 1 4 0 Updated Mar 10, 2025
  • model-condo-avm Public

    Automated valuation model for all class 299 and 399 residential condominiums in Cook County

    R 10 AGPL-3.0 4 2 0 Updated Mar 10, 2025