Thousands of Cook County residents are pre-paying their 2017 property taxes ahead of coming changes in the federal tax code. The new tax law passed by Congress this week includes a $10,000 cap on state and local tax deductions — which is set to go into effect on January 1st. That’s a big change from the previous limit — there wasn’t one. In response, about 24,000 Cook County residents have already paid their 2017 property taxes — last year, only about 1800 people did so, according to county data. While many people are paying their taxes early it’s unclear how the pre-payments will be interpreted by the IRS.