Experimental Design
We implement a 2×2 factorial experiment embedded within a baseline survey administered to approximately 34,000 students across roughly 100 schools, 1,200 classrooms, and 47 vocational tracks in São Paulo, operated by SENAI-SP.
Both treatments are randomized at the **classroom level** to limit within-class contamination and spillovers during survey administration.
Classrooms are assigned to one of four strata groups before randomization, based on data availability:
1. Standard tracks (≥10 classes per track): Each track forms its own stratum; classrooms randomized into all four arms. Combined with small tracks, this group comprises 1,092 classrooms (~30,600 students), with 273 classrooms per arm.
2. Small tracks (<10 classes per track): Pooled into sector-level strata when the sector contains at least 10 classes; randomized into all four arms. Included in the 1,092 classroom count above.
3. Early-survey classrooms (5 schools, surveyed before soft skill percentile scores are available): 61 classrooms (~1,700 students). Cannot receive the SS treatment; randomized into LM or Control only (30 control, 31 LM).
4. No RAIS match classrooms (11 tracks without RAIS–SENAI administrative match data): 46 classrooms (~1,300 students). Cannot receive the LM treatment; randomized into SS or Control only (23 per arm).
5. Both constraints (early-survey and no RAIS match): 2 classrooms (~55 students). Assigned to Control only.
This yields unequal arm sizes: Control 328 classrooms (~9,200 students), LM only 304 (~8,500), SS only 296 (~8,300), LM+SS 273 (~7,600). Total: 1,200 classrooms, approximately 34,000 students.
All estimation uses classroom-level clustered standard errors and includes strata fixed effects.