Governments across both the developing and developed world are experimenting with private management of public schools to better serve the poorest, and most under-served students. But have recent innovations lived up to their promise of improved results?
The verdict from a recent review of America’s ‘charter schools’ —the most rigorous analysis of privately-managed schools to date—suggests some cause for optimism, at least at the middle school level. What is more, recent studies show that successful ideas from the private sector can feed back into the public sector to improve education for all.
Charter Schools in America Can Improve Results
In The Effect of Charter Schools on Student Achievement: A Meta-Analysis of the Literature , Julian Betts and Emily Tang review 40 existing high-quality studies of charter school achievement. They find that the largest effect is for math achievement in middle schools, where on average, a charter school student gains about two percentile points per year relative to students in public schools. That is, a student who outscored 50 out of 100 students in public school would outscore 52 out of 100 students after one year in a charter school. Although modest, the accumulation of these gains over several years could be quite meaningful.
Students in the Knowledge Is Power Program (KIPP)  charter schools, which focus on serving students from under-served communities for success in college and in life, also show significant improvements in both math and reading scores. It is estimated that a student initially at the 50th percentile, can move to the 59th percentile in math and the 54th percentile in reading, after a single year in the KIPP program. This is confirmed by recent studies of KIPP schools by Angrist and others , which focus on low income and minority students.
A recent study from Boston demonstrates that charter schools raised mathematics scores by more than half a standard deviation per year in middle school (Abdulkadiroglu and others ). And a study of New York City's Harlem Children’s Zone , a program which serves poor minority students, finds that students enrolled in the program's charter schools in grade 6 gain more than one standard deviation in mathematics and between one third and one half a standard deviation in English by grade 8 (Dobbie and Fryer ).
“No Excuses” Improves Student Attainment
The studies mentioned above offer some clues on how charters can be more effective than traditional public schools. For example in Explaining Charter School Effectiveness, Angrist and others highlight the ‘no excuses’ model many charter schools follow, which emphasizes key factors such as:
• Student behavior and comportment;
• Traditional reading and math skills;
• An extended school day and year;
• Selective hiring;
• Strict behavior codes;
• A strong work ethic; and,
• Contracts between the school and parents.
The success from the “no excuses” approach has cross-pollinated, with a recent experiment taking five of these strategies back to the public sector in nine of the lowest performing public schools in Houston, Texas. Fryer  shows that the average impact of these changes on student achievement was 0.276 standard deviations in math and 0.059 standard deviations in reading, which is strikingly similar to the reported impacts of attending the Harlem Children’s Zone and KIPP schools which also follow the no excuses approach.
These findings have important implications for education policy in developing countries:
(1) Experiments with the Private Sector Can Payoff: the recent growth of private schools for the poor in many countries (such as Pakistan ) provides policy makers with adequate opportunities to experiment with such approaches.
(2) Impact Evaluations are Crucial: given the buzz that often surrounds private sector innovations in education, it is important to base investment on rigorous impact evaluations, rather than ideology.
(3) Innovation from Private to Public: Extending school autonomy to public and publicly-financed private schools can produce innovations that can then feedback into the larger public systems.
For more information on these and other experiences see the World Bank-CFBT Engaging the Private/Non-State Sector in Education toolkit .