Do Test Scores Help Teachers Give Better Track Advice to Students? A Principal Stratification Analysis

TL;DR

This study investigates whether providing standardized test scores to teachers improves the quality and fairness of secondary school track recommendations, using a novel principal stratification approach on Dutch data.

Contribution

It introduces a new principal stratification metric and welfare analysis to evaluate test-score access effects on recommendation quality and equity.

Findings

Test-score access increases successful placement in demanding tracks by at least 6%.

It causes 7% misplacement of weaker students.

Test-score access improves fairness for immigrant and low-SES students.

Abstract

Every year, over one million EU students choose a secondary school track based on teacher recommendations, yet little evidence shows this yields optimal assignments. Using Dutch data, we examine whether access to standardized test scores improves recommendation quality. We develop a Principal-Stratification metric in a quasi-randomized setting, conduct a welfare analysis that flexibly weights short- and long-term losses, and assess principal fairness by examining whether test-score access affects equity across protected attributes. Results are robust to replacing the Exclusion Restriction assumption underlying our main identification strategy with alternative assumptions. Allowing recommendation upgrades when test scores exceed expectations increases successful placement in more demanding tracks by at least 6%, while misplacing 7% of weaker students. Only unrealistically high weights on short-term losses would justify banning such upgrades. Test-score access also yields fairer recommendations for immigrant and low-SES students. Our methodology and findings contribute to the literature on algorithm-assisted human decisions.