This paper evaluates the impact of three different performance incentives schemes using data from a social experiment that randomized 88 Mexican high schools with over 40,000 students into three treatment groups and a control group. Treatment one provides individual incentives for performance on curriculum-based mathematics tests to students only, treatment two to teachers only and treatment three gives both individual and group incentives to students, teachers and school administrators. Program impact estimates reveal the largest average effects for treatment three, smaller impacts for treatment one and no impact for treatment two.