The 2006 data are now published, and once again the Cook County Assessor has overassessed houses (and the lots they occupy) in Chicago relative to vacant land.  As in the previous year, data from actual sales show that, as a percentage of  sales price, assessments on houses (including land) average 50% higher than assessments on vacant land. This is the reverse of the legal requirement, under which real estate which includes houses is supposed to be assessed at a 1/3 lower percentage of value than vacant land.

This amounts to is a further penalty on homeowners (and owners of condo’s, and 2-4 flats, too), as owners of vacant land aren’t carrying their legal (let alone fair) share of the tax burden.

Is Cook County uniquely corrupt or incompetent in this regard? Other Illinois counties do not even pretend to assess residential parcels at a lower percentage of value than vacant parcels.  Rather, they are obligated to assess everything at the same percentage of value.   In most cases where data are reported, however,  the assessment as a percentage of sales price is considerably lower for vacant parcels than for improved real estate.

Source: Data compiled by the Illinois Department of Revenue, which can be seen here (look at the “ratio” links under “property tax.”