Chicago Public Schools officials freshened their economic offer to teachers Wednesday but teachers union officials immediately labeled the deal “unacceptable’’ and held firm to a Sept. 10 strike date. CPS didn’t budge from its May offer of four years of 2 percent raises, but for the first time it formally dropped the requirement that the fourth-year raise be tied to a form of merit pay and “differentiated compensation,’’ Chicago Teachers Union officials said. “I have some reasonable news: The board has moved off of merit pay,’’ CTU President Karen Lewis told reporters after the union’s House of Delegates held its …
