• Independent Reports

    Mathematica Research on KIPP Public Schools

    In 2007, KIPP commissioned independent research firm Mathematica Policy Research to conduct a multi-year study of our schools. We wanted to find out whether we were truly fulfilling our promises to students and families, and to make that information publicly known.

    Mathematica’s first two reports, released in 2010 and 2013, examined the impacts of KIPP middle schools on student achievement and behavior. A 2015 report, conducted in conjunction with our federal Investing in Innovation (i3) Scale-Up Grant, examined KIPP’s impacts in grades preK-12 as well as our middle school impacts over time. A 2017 Mathematica's report studied the impact of KIPP's pre-K programs on student learning over time. Mathematica's most recent report, released in September 2019, studied the long-term impacts of KIPP middle schools on college enrollment and early college persistence.

    • Mathematica 2019 Report

      Long-Term Impacts of KIPP Middle Schools on College Enrollment and Early College Persistence

      Released September 2019

      In 2019, Mathematica released a study showing the impact of attending KIPP middle school could erase the racial achievement gap in four-year college enrollment rates nationwide.  The study’s goal was to examine what impact KIPP middle schools have on students’ enrollment in a four-year college and what impact they had on college persistence during the first two years after high school graduation.

      The study followed 1,177 students who applied to enter one of 13 KIPP middle schools through a 5th or 6th grade admission lottery in 2008 and 2009. The study tracked these students through their middle school experiences in Los Angeles, San Lorenzo, California, San Antonio, Houston, Austin, Dallas, Washington D.C., New York City, Atlanta, East Point, Georgia and Lynn, Massachusetts.

      The findings are especially notable because it’s the first study that examines the outcomes of students who only attended the program for a short time in middle school. The KIPP students Mathematica followed for this study spent at least a year, and on average, close to three and a half years at a KIPP middle school. Mathematica’s analysis is distinct from KIPP’s reported college matriculation number (80%) which tracks students who graduated from 8th grade at a KIPP middle school or attended a KIPP high school and who enrolled to a four-year and two-year college program.

      Key Findings

      KIPP middle schools boost college enrollment. The study found “attending KIPP following a middle school lottery produced an increase of 12.9 percentage points in enrollment rates in four-year college programs,” which means that “the impact of attending a KIPP school would be almost large enough to erase the nationwide racial disparity in college enrollment rates.” The national gap in college enrollment rates in 2017 between White students and Black or Latinx students for any college type was approximately 14 percentage points.

      Students who attended a KIPP middle school were more likely to enroll in a four-year college program right after high school. Overall 52 percent of students who attended KIPP enrolled in a four-year college within two years after high school graduation, compared to 39 percent who did not attend KIPP.

      Students who attended a KIPP middle school persisted at higher rates in the first two years of college, than those who did not attend a KIPP middle school.  Given the age of the students, Mathematica was only able to follow students through their first two years of college. The study showed a positive upward trend on college persistence but not yet statistically significant.  According to the study “33 percent of students who attended KIPP enrolled immediately in a four-year college program after high school and persisted in college for four consecutive semesters, compared to 24 percent of students who did not attend KIPP.”

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    • Mathematica 2017 Report

      Pre-Kindergarten Impacts Over Time: An Analysis of KIPP Charter Schools

      Released August 2017

      In 2017, Mathematica built on a previous study of KIPP elementary schools to estimate the impact of an offer of admission to a KIPP Pre-K program and explore whether any impacts persist as students advance beyond kindergarten. In the report, early evidence suggests KIPP Pre-K programs have lasting positive impacts on student achievement. Researchers collected data from KIPP SHINE and KIPP SHARP in Houston and KIPP LEAP in Washington, DC for this study.

      Key Findings

      • KIPP pre-K has a significant positive impact on student achievement: After five years, students who won an offer of admission to a KIPP pre-K program through a random lottery had higher reading and math achievement than pre-K students who did not win an offer. For example, the study showed that scores on the Letter-Word Identification (reading skills) assessment improved by nearly 14 percentage points, moving KIPP pre-K students from the 66th to the 80th percentile. On the Applied Problems (math skills) assessment, KIPP pre-K students moved from roughly the 47th to the 60th percentile.
      • KIPP early childhood programs may help students gain executive functioning skills: KIPP pre-K combined with KIPP early elementary school may also positively affect students’ executive function, including their working memory and ability to follow instructions, although most findings were not significant. Executive function skills are widely believed to be related to students’ long-term academic success.
      • KIPP pre-K appears to offer an additional benefit above and beyond the impact of the KIPP elementary grades: The reading impacts of KIPP elementary schools that offered pre-K were larger than those of KIPP elementary schools that did not offer pre-K, although the differences were not statistically significant.
      • The impact of KIPP pre-K on reading skills persists into second grade: Students who won an offer of admission to KIPP pre-K appear to maintain an advantage in reading skills over their second-grade peers who did not win an offer. The size of their advantage in reading comprehension appears to decrease, but not disappear, over time. Although some studies show that the positive impacts of some pre-K and other early childhood programs eventually decrease or disappear, this study suggests that the combination of KIPP pre-K and KIPP early elementary school may have more lasting impacts.


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      Related Media

      “New Study: KIPP Pre-K Has Big — and Possibly Lasting — Impact on Early Student Achievement”
      The 74 Million, August 2017

      “5 Key Things You Need to Know About Important New Study on the Benefits of KIPP Pre-K”
      The 74 Million, August 2017

    • Mathematica 2015 Report

      Understanding the Impact of KIPP as it Scales

      Released September 2015

      In 2015, Mathematica released the report from their five-year i3 Scale-Up Grant Evaluation of KIPP Public Schools. This is the first report ever to include KIPP schools at all K-12 levels, including elementary and high schools as well as middle schools. The report also examines KIPP’s middle school impacts over the past decade.

      Key Findings

      • KIPP elementary schools have positive, statistically significant, and educationally meaningful impacts on three of four measures of reading and mathematics skills.
      • Consistent with prior research, KIPP middle schools have positive, statistically significant, and educationally meaningful impacts on student achievement in math, reading, science, and social studies. Average impacts of middle schools were positive and statistically significant throughout the 10-year period covered by the study, though higher in earlier years than recent years.
      • KIPP high schools have positive, statistically significant, and educationally meaningful impacts on student achievement for high school students new to the KIPP network. For students continuing to KIPP high schools from KIPP middle schools, impacts on achievement are not statistically significant. For this group of continuing KIPP students, KIPP high schools have positive impacts on a variety of college preparation activities and the likelihood of applying to college.
      • On surveys of student motivation, engagement, behavior, and educational aspirations, KIPP schools showed no significant impact. However, KIPP elementary and middle schools had positive impacts on parent satisfaction.


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      Related Media

      “KIPP charter school students show lasting achievement gains, study finds”
      Houston Chronicle, September 2015

      “Study: Nation’s largest charter school network has huge educational impact” 
      Washington Examiner, September 2015

    • Mathematica 2013 Report

      KIPP Middle Schools: Impacts on Achievement and Other Outcomes

      Released February 2013

      In 2013, Mathematica released the second report from their multi-year study of KIPP middle schools. This report looks at KIPP’s middle school impacts on student achievement and other outcomes, while also addressing prevalent myths around KIPP’s enrollment practices, attrition, and parental motivation.

      Key Findings

      • KIPP middle schools have positive and statistically significant impacts on student achievement across all years and all subject areas examined. According to a matched comparison design study, KIPP students showed gains in math, reading, science, and social studies on state assessments.  This finding confirms that we have been able to maintain the quality of our middle schools as we have expanded our network.
      • The magnitude of KIPP’s achievement impacts is substantial. Across all grade levels and subjects studied, KIPP’s achievement impacts are large enough to be educationally significant.
      • The matched comparison design produces estimates of KIPP’s achievement impacts similar to estimates of the same impacts based on an experimental, lottery-based design. Researchers found that KIPP’s achievement gains are similar for the matched comparison design and the experimental lottery analysis–demonstrating that parental motivation cannot explain our student’s achievement gains.
      • In the lottery sample, average KIPP impacts on a nationally normed test that includes items assessing higher-order thinking skills were similar to impacts on high-stakes state tests. For students in the lottery sample, gains on the national norm referenced test mimicked those on state tests.


      Executive Summary Download Full Report

      Related Media

      “Mathematica 2013 Study: KIPP Charter School Students Outperform Public School Peers” 
      Huffington Post, February 2013

      “KIPP Schools Boost Academic Performance, Study Finds” 
      Education Week, February 2013

    • Mathematica 2010 Report

      Student Characteristics & Achievement in 22 KIPP Middle Schools

      Released June 2010

      Mathematica’s first major study on KIPP Public Schools was released in 2010. At the time, this report was the first to apply a rigorous methodological approach to studying achievement across multiple KIPP schools.

      Key Findings

      • The vast majority of KIPP middle schools produced positive and statistically significant impacts on student achievement. Students from these schools showed gains in reading and math in all four years after they entered KIPP.
      • Achievement gains at KIPP middle schools are large. Three years after entering KIPP schools, many students experience achievement gains that are approximately equivalent to an additional year of instruction—enough to substantially narrow race- and income-based achievement gaps.
      • Students who enter KIPP middle schools typically have lower achievement than the average for their school districts. Compared to neighboring district schools, KIPP middle schools have student bodies characterized by higher concentrations of poverty and racial minorities, but lower concentrations of special education and limited English proficiency students.
      • Most KIPP middle schools do not have higher levels of attrition than nearby district schools. When compared to other surrounding public schools, Mathematica’s researchers did not find a pattern of high attrition among the 22 KIPP schools they studied.


      Executive Summary Download Full Report

      Related Media

      “Study supports KIPP success; Review shows school isn’t gaming system”
      Houston Chronicle, June 2010

      “KIPP Middle Schools Found to Spur Learning Gains”
      Education Week, June 2010

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