As part of a multi-state evaluation project on the impact of charter school attendance on student achievement, we put together and analyzed panel data on Milwaukee Public School (MPS) students spanning the 2000-01 through 2006-07 school years. Specifically, we employed “fixed effects” models to estimate the impact of charter school attendance on student gain scores on mathematics and reading achievement tests. We found that:
- charter school attendance is associated with higher scores on mathematics exams than attendance at traditional public schools, but there is no statistically significant relationship between charter school attendance and performance on reading exams;
- positive results in mathematics are due to student performance in the initial years of the program—the performance of charter schools and traditional public schools is statistically indistinguishable for the most recent years of our study;
- the positive impact of charter schools on achievement (relative to traditional public schools) declines as the number of years a student has attended a charter school increases;
- charter schools that have operated for a number of years and those that had been traditional public schools drive the positive charter school results;
- student mobility has a negative effect on performance and it is a more robust predictor of student performance than the organizational factors we consider;
- there is no evidence that the presence of charter schools induces better student performance in traditional public schools.
We conclude that while charter schools overall may help the education of urban youth, our study of Milwaukee indicates that they should not be expected to be the silver bullet that some reformers seek. We also suggest that it is important to better understand and deal with instability in school attendance in urban school districts, as it proves to be the most significant determinant of student achievement in all of our statistical models.