Charter Schools: Facts & Issues
Published by the
LWVAL Education Fund
April 2011

VIII.   Studies looking at charter school efficacy

There are numerous reports and news story highlighting the success of charter schools. Newsweek observed that at least 15 of the schools on its 2010 list of top public high schools were charter schools23 In 2008, the U.S. Department of Education released "A Commitment to Quality: National Charter School Policy Forum Report" that highlighted some of these success:24

  • Amistad Academy in New Haven, where 84 percent of the middle-schoolers are low-income, outperforms Connecticut‘s students in both reading and math based on the average state test scores, with 80–85 percent of students passing the tests.
  • During the 2006–07 school year, 100 percent of the third- and fourth-graders—90 percent of whom are from low-income families—at Carl C. Icahn Charter School in the Bronx scored proficient and above on the state mathematics exam, compared to 61 percent of third-graders and 52 percent of fourth-graders in the district.
  • According to a 2008 RAND study of Chicago‘s charter schools, 49 percent of eighth-grade charter school students who go on to attend a charter high school are likely to enroll in college five years later. Only 38 percent of eighth-grade charter school students who transfer to a district high school are likely to do so.

A January 2010 report by the Center for Research on Education Outcomes (CREDO) at Stanford University found that "charter schools in New York City are demonstrating significantly better results for their students in reading and in math than their traditional public school counterparts. These trends were consistent for students overall, as well as for several key groups, including Blacks and Hispanics in both subjects, for students who had not previously done well in traditional public schools, for students in poverty in reading, for students enrolled for at least two years or more in reading, and for all students in math regardless of how long they were enrolled."25

A 2009 study on charter schools in eight states by the RAND Corporation, which it claimed was the first to examine the effects of charter schools on long-term attainment outcomes, found that in the two locations (Florida and Chicago), "…attending a charter high school is associated with statistically significant and substantial increases in the probability of graduating and of enrolling in college."26 The same report also noted that there was no dramatic shifts by race or ethnicity in any of the schools in the study and the racial composition of the charter schools were similar to that of the traditional public schools from which the students transferred.

The research by Carolyn Hoxby, Sonali Murarka, and Jenny Kang on New York City charter schools, published in 2009, was based on a multi-year study that involved the majority of the city‘s charter schools and followed the progress of students in grades 3-12 who either were selected by lottery to attend a charter school (lotteried-in) or remained in a traditional public school after not being selected for a charter school by lottery (lotteried-out). The findings related to achievement included:27

  • Charter school applicants are much more likely to be black and much less likely to be Asian or white than the average student in New York City‘s traditional public schools.
  • Charter school applicants are more likely to be poorer than the average student in the city‘s traditional public schools.
  • Based on data estimates, on average, a student who attended a charter school for all of grades kindergarten through eight would close the achievement gap (between students in affluent locations and students in much less affluent locations) in math and English.
  • "Lotteried-in" students who attend a charter high school have higher graduation examination scores than "lotteried-out" students (about 3 points for each year in a charter school before taking the test.) For instance, a student who took the English Comprehensive exam after three years in charter school would score about 9 points higher.
  • Students who attend a charter high school are about 7 percent more likely to earn New York‘s Regents diploma (a level of high school graduation based on test scores) by age 20 for each year spent in that school. For instance, a student who spent grades ten through twelve in charter high school would have about a 21 percent higher probability of getting a Regents diploma.

In a 2009 report on a study tracking charter students, CREDO found that "… a decent fraction of charter schools, 17 percent, provide superior education opportunities for their students. Nearly half of the charter schools nationwide have results that are no different from the local public school options and over a third, 37 percent, deliver learning results that are significantly worse than their student would have realized had they remained in traditional public schools. These findings underlie the parallel findings of significant state‐by‐state differences in charter school performance and in the national aggregate performance of charter schools."28 The study used longitudinal student‐level achievement data from 15 states and the District of Columbia to create a virtual twin of charter school students based on students who match the charter student‘s demographics, English language proficiency and participation in special education or subsidized lunch programs. The report noted that virtual twins were created for 84 percent of the students in the study‘s charter schools. The Center for Public Education created this chart29 using CREDO findings:


The U.S. Department of Education released the study, "Evaluation of Charter School Impacts," in 2010. This study involved 36 charter middle schools across 15 states, and tracked students who entered a charter school lottery, and were either accepted and attended a charter school or not accepted and attended a traditional public school. Key findings from the evaluation included:30

  • On average, the charter middle schools in the study were neither more nor less successful than the traditional in improving student achievement, behavior, and school progress.
  • The impact of charter middle schools on student achievement varies significantly across schools.
  • The studied charter schools serving more low income or low achieving students had statistically significant positive effects on math test scores, while charter schools serving more advantaged students—those with higher income and prior achievement—had significant negative effects on math test scores.
  • Some operational features, including smaller enrollments and ability grouping in math or English classes were associated with positive impacts on achievement. Longer- versus shorter- hours of operations and higher versus lower revenue did not play a significant role in achievement. Nor were there statistically significant relationships between achievement and the charter schools‘ policy environment, including the extent of its decision-making autonomy, the type of authorizer and how the authorizer held the school accountable, and whether it was operated by a private organization.

A Newsweek article on charter schools offered this summary: "Generally speaking, in states and cities where the bar is set high for both entry and performance (Boston, New York, D.C., Chicago), charter schools do well. In states that started with the loosest oversight (Arizona, Florida, California, Ohio, and Texas), there‘s much more of a mixed bag."31

Diane Ravitch (former assistant secretary of education under former President George H.W. Bush and author of The Death and Life of the Great American School System: How Testing and Choice Are Undermining Education) takes a more critical view of charter schools. In a March 2010 editorial to the Wall Street Journal, she said, "Given the weight of studies, evaluations and federal test data, I concluded that deregulation and privately managed charter schools were not the answer to the deep-seated problems of American education. If anything, they represent tinkering around the edges of the system. They affect the lives of tiny numbers of students but do nothing to improve the system that enrolls the other 97%."32

© 2011 League of Women Voters of Alabama Education Fund. All rights reserved.