How Charter Schools Affect Student Outcomes

For Release

March 18, 2009

While the number of charter schools continues to grow, debate continues about whether charter schools provide a better education experience than traditional public schools. Proponents contend that charter schools expand educational choices for students, increase innovation, improve student achievement and provide much-needed competition to public schools.

Opponents, meanwhile, argue that charter schools lead to increased racial or ethnic stratification of students, skim the best students from traditional public schools, reduce resources for public schools and provide no real improvement in student achievement.

A new RAND Corporation study examining charter schools in Chicago, San Diego, Philadelphia, Denver, Milwaukee, and the states of Ohio, Texas and Florida is the first to use longitudinal, student-level data to systematically examine these issues across multiple communities and varied charter laws. It finds that:

  • Across locations, there is little evidence that charter schools are producing, on average, achievement impacts that differ substantially from those of traditional public schools. But the evidence is incomplete, because the performance of charter elementary schools -- which constitute a substantial proportion of all charter schools -- cannot be easily assessed. Many students who attend an elementary charter school enter at Kindergarten, and test scores for these students prior to entering Kindergarten are unavailable.
  • There is reason for concern about low performance among two specific groups of charter schools: charter schools in their first year of operation; and, in Ohio, “virtual” charter schools that serve students remotely via technology rather than in a conventional school building.
  • The most promising results for charter schools relate to the long-term outcomes of high-school graduation and college entry. In the two locations with available data on these critical attainment outcomes (Chicago and Florida), charter high schools appear to have substantial positive impacts, increasing the probability of graduating by 7 to 15 percentage points and increasing the probability of enrolling in college by 8 to 10 percentage points.
  • Across seven locations examined, charter schools are generally not “skimming the cream” in recruiting students: Students entering charter schools generally have prior achievement levels that are comparable to those of their peers in traditional public schools.
  • Across locations, charter schools do not appear to produce effects that substantially help or harm student achievement in nearby traditional public schools

“While the lack of positive effects on test scores may be disappointing to charter advocates, the positive relationships between charter high school attendance and graduating and going on to college in Chicago and Florida are encouraging,” said Ron Zimmer, the report’s lead author. “These results suggest it may be time to include other important measures when evaluating charter schools.”

The report, “How Charter Schools Affect Student Outcomes,” can be found at <> . The report was conducted as a collaboration between RAND Education, Mathematica Policy Research, Inc., and Florida State University. Support was provided by the Bill and Melinda Gates Foundation, the Joyce Foundation, the Stranahan Foundation and the William Penn Foundation.

The report authors are Ron Zimmer of Michigan State University, Brian Gill and Kevin Booker of Mathematica Policy Research, Tim Sass of Florida State University, and Stéphane Lavertu and John Witte of University of Wisconsin.

RAND Education, a division of the RAND Corporation, is a leader in providing objective, reliable research and analysis on educational challenges that is used to improve educational access, quality and outcomes in the United States and throughout the world.

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