Working Paper: NBER ID: w14778
Authors: Cory Koedel; Julian Betts
Abstract: Value-added measures of teacher quality may be sensitive to the quantitative properties of the student tests upon which they are based. This paper focuses on the sensitivity of value-added to test-score-ceiling effects. Test-score ceilings are increasingly common in testing instruments across the country as education policy continues to emphasize proficiency-based reform. Encouragingly, we show that over a wide range of test-score-ceiling severity, teachers' value-added estimates are only negligibly influenced by ceiling effects. However, as ceiling conditions approach those found in minimum-competency testing environments, value-added results are significantly altered. We suggest a simple statistical check for ceiling effects.
Keywords: Value-added; Teacher quality; Test-score ceilings; Educational policy
JEL Codes: I21; I22; J08; J33; J45
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| test-score ceiling effects (C24) | value-added estimates of teacher quality (J24) |
| severe ceiling conditions (L74) | value-added estimates of teacher quality (J24) |
| lost information about student learning (A21) | value-added estimates of teacher quality (J24) |
| model misspecification (C52) | value-added estimates of teacher quality (J24) |
| test-score ceiling effects (C24) | correlation between teacher value-added estimates before and after imposing ceilings (C21) |