The 1999 Performance Levy Math

Technique: conflating relative change with percentage points

The site says teacher raises were tied to a "25-percentage-point gain" in performance. The actual target was a 25% relative gain, from 53.2% to 66.5%, which works out to about 13 percentage points, roughly half what the site implies. The payoff also went to the district as general revenue, not specifically to teacher raises.