Explaining Charter School Effectiveness
Angrist JD, Pathak PA, Walters CR · 2013
grade Anatural-experimentindependentunreplicated
Sample
Massachusetts charter lotteries, urban and non-urban schools, pooled with observational estimates for non-lottery schools
Population
Massachusetts charter applicants.
Design
Same lottery machinery as the Boston study, extended statewide so that urban and non-urban charters can be compared under one design. This is what turns 'charters work' into a statement about intake and model rather than about the sector.
Key findings
The same sector, the same state and the same design give +0.34 SD/yr in urban schools and -0.16 in non-urban ones. For an advantaged intake, grade-A evidence for the No-Excuses model is absent to negative. Match the model to the intake; math always moves 2-5x more than reading.
Genetic confound
Lottery-identified within applicants. Urban gains are partly recovery from a weak counterfactual school rather than absolute instructional superiority.
Replication notes
The sharpest demonstration of intake-dependence in the charter literature.
DOI / URL
Effects
| Outcome | Metric | Value | Measure | Timing | Vs | Horizon | Class |
|---|---|---|---|---|---|---|---|
| Urban Massachusetts charters | SD/yr | +0.34 math | standardized | per year of attendance | business-as-usual | end-of-treatment | domain-skill |
| Non-urban Massachusetts charters (same design, advantaged intakes) | SD/yr | -0.16 math — NEGATIVE | standardized | per year of attendance | business-as-usual | end-of-treatment | domain-skill |
| What explains the urban/non-urban gap | decomposition | adoption of No-Excuses practices and the achievement level of the intake; gains are larger for LOWER-baseline students and are not peer-driven | standardized | n/a | unclear | unclear | domain-skill |
Cited by
- School spending, charters, and what school-level choices actually move outcomesmixedconf: highgc: low