Student Achievement Gains at KIPP Schools Cannot Be Explained by Student Attrition

Ira Nichols-Barrer:, 617-674-8364, Mathematica Policy Research
Brian Gill:, 617-301-8962, Mathematica Policy Research
Ashley Inman:, 707 332-1184, Education Next Communications Office 

Student Achievement Gains at KIPP Schools Cannot Be Explained by Student Attrition

Study finds students are similar to those in other local schools and most patterns of attrition are no different

The Knowledge Is Power Program (KIPP) is a network of charter schools, a majority of which are 5th-through 8th-grade middle schools, designed to improve education opportunities available to low-income families. Several rigorous studies have confirmed that many KIPP middle schools have large, positive impacts on student performance in math and reading tests.

Now a recent study in Education Next from researchers at Mathematica Policy Research examines whether KIPP’s positive effects are attributable to better peers, which would consequently make it difficult to replicate the KIPP model and academic successes in public schools.

Using detailed student-level data to compare what sorts of students enter KIPP as compared to public schools in the neighborhood, and what kinds of students replace those who leave, authors find, on average, that KIPP middle schools admit students who are similar to those in other local schools. The data also indicate that patterns of student attrition at KIPP schools are typically no different from other local schools except that KIPP schools replace vacancies with fewer students in the last two years of middle school, and those late-arriving students are somewhat higher-achieving than students entering KIPP schools in 5th and 6th grades.

Students entering KIPP schools in 5th grade had similar pre-KIPP test scores as students who remained in district schools. Due to the attrition and replacement of students during the course of middle school, however, KIPP’s eighth-grade students had pre-KIPP test scores that were about 6 to 7 percentile points higher than the test scores of students in district schools. Nonetheless, the researchers found that this pattern of replacement and selection is unlikely to explain more than one-third of the cumulative KIPP impact.

“One implication of these findings is that the KIPP model may include practices that could be effective outside schools of choice,” the authors observe. “Whether these practices can be replicated in traditional public schools or raise academic achievement across the full range of traditional public-school students remains to be seen.”

Does Student Attrition Explain KIPP’s Success: Evidence on which students leave KIPP middle schools and who replaces them,” by Ira Nichols-Barrer, Brian P. Gill, Philip Gleason, and Christina Clark Tuttle, is available on and will appear in the Fall 2014 issue of Education Next.  The authors are available for interviews.

About the Authors

Ira Nichols-Barrer is a researcher at Mathematica Policy Research, where Brian Gill and Philip Gleason are senior fellows and Christina Clark Tuttle is a senior researcher.

About Education Next

Education Next is a scholarly journal published by the Hoover Institution that is committed to careful examination of evidence relating to school reform. Other sponsoring institutions are the Program on Education Policy and Governance at Harvard University, part of the Taubman Center for State and Local Government at the Harvard Kennedy School, and the Thomas B. Fordham Foundation. For more information about Education Next, please visit:

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