The Illinois Department of Revenue (the Department) recently released the tentative 2010 equalization factor or “multiplier” for Cook County.  Based on its analysis of assessed values, property transfers, and other information, the Department announced a tentative multiplier of 3.1773.

The Property Tax Code requires the Department to issue a multiplier that, when applied to the assessed value of all property in a county (except for specially assessed property such as farmland), will result in the aggregate assessed value of all property in the County being 33.33% of the property’s fair cash value.  This equalization of assessed values is accomplished by comparing recorded sales prices to assessed values for the three prior years, and it is done in an effort to implement property tax limitations and certain state funding programs fairly.

The tentative multiplier is only an estimate by the Department.  It is being released before the Board of Review has certified the final 2010 assessments.  As a result, it does not account for changes in the assessments that the Board of Review may make.  A summary of the tentative and final multipliers for the last six years is as follows.

 Click here to view table.

It is always difficult to predict what the final multiplier will be based on the tentative multiplier.  Based on the difference between the 2009 tentative and final multipliers, one could expect the 2010 final multiplier to again be around 3.3.

The Department's press release also contains the three-year average assessment levels for commercial, industrial, and residential property as indicated by the Department’s sales ratio study.  The three-year average assessment level indicated by the sales ratio for commercial property is 16.19%, for industrial property 18.64%, and residential property 9.08%.