Illinois property taxes are now so high that they are equivalent to a second mortgage, according to a new study from the nonpartisan Tax Foundation, a Washington-based tax-research and -education center. The report, which shows the effective property-tax rates in each state, ranks Illinois as the second-highest property-tax state in the U.S. The top spot goes to New Jersey, where the effective property-tax rates is 2.38 percent, barely higher than Illinois’ 2.32 percent.