Minimum detectable effect size for main outcomes (accounting for sample
design and clustering)
Power calculations follow Duflo, Glennerster, and Kremer (2007) and assume 189 schools, 8,505 students, an intracluster correlation of 0.06, 80 percent power, and a significance level of 0.05. For entry into vocational training, with a control-group mean of 10 percent (estimated from administrative data), the minimum detectable effect is 3.6 percentage points, or 36 percent of the control mean. For attainment of at least a lower secondary school certificate, with a baseline of 27 percent (KMK 2024), the minimum detectable effect is 5.3 percentage points, or 19.6 percent of the control mean. Conditioning on pre-treatment outcomes in the difference-in-differences specification is expected to reduce these values further, by an amount that depends on the serial correlation of the outcomes across cohorts.