In perhaps a troubling sign, Denver Public Schools is reporting that teachers are leaving its school system at a much higher rate than in years past. Last summer, 231 teachers moved out of the Denver system between May and August, as compared to 136 teachers in the same months of 2002 and 179 teachers in 2003.

The Denver Post’s article on the “exodus??? attributes it to a general combination of teacher dissatisfaction with testing standards, a salary freeze, retirement plan worries, and comparatively nice conditions in surrounding districts. All of these are certainly factors, but the article fails to mention why Denver’s much lauded new pay-for-performance program isn’t persuading teachers to stay put. It’s important to find out if this program is actually causing more teachers to leave the system. One can only speculate that the program is forcing weaker teachers to leave because they are either hesitant about declining to participate in the program (which is voluntary) or about setting goals for which they will be held accountable. But that is only speculation.