Cook County has opted into a new property tax law that will limit annual increases in assessed valuation to 7 percent on residential property. County commissioners voted 16 to one in favor of the cap a day after Governor Rod Blagojevich signed a state law that allows Illinois counties to impose the three-year limit.
Under the plan, a $100,000 home whose value increased to $130,000 would only be taxed at a value of $107,000. The home would be taxed based on a value of $114,000 the second year and $121,000 for the third year.

Critics contend that the measure will unfairly shift the tax burden to businesses, and some schools are worried that it will make funding education difficult.