Do Charter High Schools Improve Academic Achievement and College Enrollment Outcomes?

The primary research question of the study is to estimate the causal effects of attending high-quality charter high schools on academic achievement and college enrollment among primarily low-income Black and Latino students in Los Angeles. Using a lottery-based design, the researchers analyzed eleventh-grade standardized test scores, high school coursework, GPA data, and college enrollment outcomes. Findings indicate that charter school enrollment significantly improved test scores (by 0.29-0.33 SD), increased four-year college enrollment by 19 percentage points, and UC campus persistence by 12 percentage points. However, no effect was found on high school GPA.

Extended Summary

Central Research Question

The primary research question explored in this study is: What are the causal effects of enrolling in high-quality charter high schools on academic achievement and college enrollment for primarily low-income, Black and Latino students in Los Angeles? The researchers investigate how charter schools influence key educational outcomes, including standardized test scores, advanced coursework, GPA, college application rates, and persistence in four-year colleges. The focus is particularly on assessing whether these schools help mitigate disparities in college enrollment and persistence by supporting students' academic growth and readiness for higher education.

Previous Literature

The study builds on an extensive body of literature examining the impact of charter schools, especially in urban environments. Prior research has shown mixed outcomes, with some studies highlighting significant positive effects on student test scores and college enrollment (e.g., Boston’s charter schools). Specifically, urban “no excuses” charter schools, which follow strict academic and behavioral guidelines, have often demonstrated the ability to improve student performance and postsecondary outcomes. However, other research, including some that utilized lottery-based designs, indicated smaller or negligible effects, particularly when examining non-urban charter schools.

The authors reference a range of studies exploring the broader topic of high school quality and its influence on college enrollment, noting that the literature has pointed to both academic preparation and the high school environment as critical factors. They also discuss how barriers such as socioeconomic status and inadequate support during the college application process contribute to disparities in higher education attainment. By integrating these findings, the study aims to determine whether charter schools can effectively address these challenges for disadvantaged populations.

Data

The researchers employed data from a lottery-based design involving five oversubscribed high-quality charter high schools in Los Angeles. The sample primarily consisted of low-income Black and Latino students who applied to enter these charter schools in 9th grade during 2013 and 2014. The total study sample included 1,270 students, split between lottery winners (those admitted to the charter schools) and lottery losers (those who were not admitted and who attended various other schools).

Data sources used in the analysis included:

Administrative Records: Data on standardized test scores (Smarter Balanced Assessment Consortium scores), high school GPA, course enrollment records, and college enrollment information obtained through the National Student Clearinghouse.
Surveys: Information gathered through surveys on students’ perceptions of teacher support, academic attitudes, effort, and delinquency.
High School Transcripts: Detailed information on coursework completed, particularly in advanced subjects like math and Advanced Placement (AP) classes.

Methods

The study uses a lottery-based approach to estimate the causal impact of charter school enrollment. The researchers leveraged the random assignment inherent in the lottery system as an instrument for school attendance, enabling them to compare outcomes between students who won and those who lost the lottery. This method helps isolate the effect of attending a high-quality charter school from other confounding factors that could influence educational outcomes.

A two-stage least squares (2SLS) model was used to estimate the treatment effects, with the first stage predicting the likelihood of enrollment based on winning the lottery, and the second stage estimating the impact on outcomes like test scores, college enrollment, and persistence. The analysis included controls for baseline characteristics such as 7th-grade test scores and 8th-grade GPA, as well as demographic variables (e.g., race, gender, parental education). This design aimed to control for differences in prior academic achievement and demographic factors, thereby ensuring the validity of the causal estimates.

Additionally, the authors conducted subgroup analyses to examine whether effects varied by prior academic achievement and gender. This allowed them to explore whether charter schools provided more significant benefits to certain groups of students within the low-income, Black and Latino populations.

Findings/Size Effects

The study found substantial positive effects of enrolling in high-quality charter high schools on various educational outcomes:

Test Scores: Charter school enrollment led to significant increases in 11th-grade math and English Language Arts (ELA) standardized test scores. Specifically, the effect sizes were approximately 0.29 and 0.33 standard deviations for math and ELA, respectively. These results indicate a meaningful improvement in academic performance for charter school attendees.
College Enrollment: Attending a charter school increased the probability of enrolling in any college by 14 percentage points compared to a control group mean of 58%. The effect was even more pronounced for four-year colleges, with an increase of 19 percentage points, and for University of California (UC) campuses specifically, with a 12 percentage point increase. These findings highlight the role of high-quality charter schools in improving college-going rates, particularly for four-year institutions.
College Persistence: The impact on persistence in four-year colleges was also notable. The study found an 11 percentage point increase in the likelihood of persisting into the second year at a four-year institution, primarily driven by enrollment in UC campuses. This suggests that the benefits of charter school enrollment extend beyond mere access to higher education, positively influencing long-term engagement and success in college.
Intermediate Outcomes: While the study observed improvements in standardized test scores and college enrollment, it did not find significant effects on high school GPA. However, charter school students reported higher levels of teacher support and a more pronounced “college-going culture,” which included increased teacher expectations and assistance with college applications. Charter students also took more advanced coursework, including higher-level math and AP classes, and reported less class-skipping behavior compared to their peers.
Subgroup Analysis: The effects were more pronounced for students with lower prior academic achievement, particularly regarding test scores and four-year college enrollment. However, the persistence benefits were more concentrated among higher-achieving students, suggesting that charter schools might be particularly effective for academically prepared students when coupled with opportunities at selective colleges like those in the UC system.

Conclusion

The study concludes that high-quality charter high schools in Los Angeles have a substantial positive impact on academic achievement and college enrollment, particularly for low-income, Black, and Latino students. These charter schools seem to create environments that encourage academic success and college preparation, reflected in higher test scores, more rigorous coursework, and a culture supportive of college enrollment.

However, the study also notes that the effects on persistence are more significant for higher-achieving students, suggesting that the success of charter schools in promoting long-term college engagement may be partly dependent on students’ initial academic standing and the availability of high-quality postsecondary institutions. The authors emphasize that while the results are promising, they are specific to oversubscribed, high-performing urban charter schools and may not generalize to all charter schools. Future research should continue to explore the mechanisms by which charter schools influence educational outcomes and the role of postsecondary institutions in supporting the long-term success of charter school students.

Full Citation

Reber, S. J., Rünger, D., & Wong, M. D. (2023). The Effects of Charter High Schools on Academic Achievement and College Enrollment: Evidence from Los Angeles. Education Finance and Policy, 19(4), 567-601. https://doi.org/10.1162/edfp_a_00411.