Education Pre K-12
January 28th, 2020 14 Minute Read Issue Brief by Max Eden

Issues 2020: Charter Schools Boost Results for Disadvantaged Students and Everyone Else

Dozens of studies of public charter schools have reached a consistent conclusion: their presence benefits disadvantaged students who attend them as well as the students who don’t.

The Narrative

"We should fight back against the privatization, corporatization, and profiteering in our nation’s schools. I did that when I opposed a ballot question in Massachusetts to raise the cap on the number of charter schools. . . . And as president, I will go further."[1]
— Elizabeth Warren


"[F]ew charter schools have lived up to their promise.... Moreover, the proliferation of charter schools has disproportionately affected communities of color."[2]
— Bernie Sanders


"The point is, if I'm president, Betsy Devos's whole notion, from charter schools to this, are gone."[3]
— Joe Biden


Dozens of studies of public charter schools have reached a consistent conclusion: their presence benefits disadvantaged students who attend them as well as the students who don’t. Studies show substantial gains in academic achievement, especially for lower-income and minority students, amounting to weeks, or even months, of additional classroom learning each year. As compared with similar peers in traditional public schools, charter students also have better outcomes on a variety of important social indicators, from higher college attendance and persistence (the percentage of students who return for their second year) to lower rates of teen pregnancy and incarceration.

Moving funds from public school districts to public charter schools can place increased strain on those districts’ budgets. But the goal of public education is not to let administrators operate underperforming schools free from competition or financial pressure; it is to educate children. As has always been the theory of school choice, competition from charter schools appears to boost the performance of nearby traditional public schools, making the majority of students who do not enroll in charters beneficiaries as well.

Key Findings

Charter schools provide substantial academic benefits for students who attend them:

  • A national study of 41 urban areas estimated that charter schools provide black students in poverty with an additional 59 days of learning in math and 44 days of learning in reading per year.
  • In a review of 15 randomized control trial studies on academic effects of urban charter schools, 12 showed significant benefits for reading and math, three showed no effects, and none showed negative effects.
  • Studies in three states have demonstrated that attending charter high schools boosts college entry and persistence.
  • Studies in two districts have shown that attending charter schools decreases criminal activity. 

Although traditional school districts receive less overall funding when students attend charter schools, charter schools have a positive effect on academic achievement for students “left behind” in traditional public schools.

  • Studies in five states have shown that competition from charter schools academically benefits students in traditional public schools.
  • A higher “market share” of charter schools in urban districts is associated with significant achievement gains for black and Hispanic students.

The minority groups that politicians say are being harmed by charter schools are most likely to support charter schools.

  • Among Democratic voters, 58% of blacks and 52% of Hispanics approve of charter schools, compared with 26% of whites.

On the Record

"Judging by the harsh turn that some politicians have taken against charter schools, voters might well imagine that the data look darker than they did when President Barack Obama championed them. That is simply not the case: studies still affirm that charters provide a substantial academic benefit for low-income students of color, benefit children who remain in traditional public schools, and provide the taxpayer with a far greater return on investment. Whatever is driving the opposition, it isn’t the data—nor is it the voices of parents of color, who are still strong charter school supporters."

—Max Eden, senior fellow, Manhattan Institute

Ten years ago, policies to expand the charter school sector were a rare spot of bipartisan agreement. Today, some presidential candidates want to restrict charter schools’ growth. What changed? Not the data. If anything, the evidence on the benefits of charter schools for low-income students has only grown stronger.

The charges leveled against charters fall into two buckets. First, in the words of Bernie Sanders, is that the “proliferation of charter schools has disproportionately affected communities of color.”[4] And second, in the words of Elizabeth Warren, is that “efforts to expand the footprint of charter schools . . . strain the resources of school districts and leave students behind.”[5]

A careful review of the evidence suggests that charter schools have indeed “disproportionately affected communities of color”—charter schools have affected these communities positively. The expansion of charter schools does indeed strain the resources of school districts—but the students “left behind” in district schools perform better academically. This makes charter schools a win-win for students, as well as for taxpayers.

Disproportionate (Positive) Impact

According to a recent report from the National Center for Education Statistics, charter school students perform, on average, no better or worse than their traditional public school counterparts.[6] But that finding reflects the aggregate performance of all students in each kind of school, without consideration of vast differences in who attends the schools and where they are located. To meaningfully evaluate charter schools, as compared with their traditional public peers, comparisons must be made between comparable students in each context.

Stanford University’s Center for Research on Education Outcomes (CREDO) has analyzed charter school outcomes across many states and regions with a methodology that compares charter students with their demographic “virtual twins” in traditional public schools. Its 2013 study, spanning 27 states, found negative effects for white students, null effects for black middle-class students, and positive effects for black and Hispanic students in poverty.[7] CREDO translates its results into “days of learning” lost or gained per year. White students lost 14 days of reading and 50 days of math (losses due, in part, to enrollment in low-performing online charter schools). Black students in poverty gained 36 days of math and 29 days of reading learning from attending charter schools; Hispanic English-language learners gained 43 additional days of reading and 50 days of math learning.

A 2015 CREDO study analyzing 41 major urban areas found a similar pattern, with even larger effects for black and Hispanic students.[8] Black students in poverty gained 59 days of math and 44 days of reading; Hispanic English-language learners gained 71 days of math and 79 days of reading.

Although the CREDO study goes to great lengths to compare demographically similar students, critics have objected that it isn’t truly a causal evaluation because it can’t detect unobservable differences between students whose parents send them to a charter school and students whose parents do not. Some academics have overcome this empirical difficulty by comparing students who won and lost admissions to charter schools through a random lottery. These studies provide researchers with greater confidence that the results they are seeing are causal, but because they can be conducted only on charters that are oversubscribed, they can view only a smaller, possibly less representative, slice of the charter sector.

In 2016, researchers from Columbia, MIT, and the University of Toronto reviewed the 15 such studies that had been conducted to date.[9] They found positive academic effects in 12 studies and no statistically significant effect in three others. In no case did the researchers identify a negative effect. The authors noted that the largest positive effects were found for students in low-performing urban areas.

There is, of course, more to life (and to school) than test scores. The literature on longer-term outcomes of charter schools is smaller and somewhat more mixed, but it is still broadly positive. On the negative-to-neutral side of the ledger, one matching study of charter schools in Texas found that they led to a small increase in college enrollment but a small decrease in adult income.[10] And a recent national lottery study of 31 charter middle schools (including only three serving predominantly low-income students) found no effect on a student’s likelihood of attending or graduating college.[11]

On the positive side of the ledger, matching studies of charter high schools in three states found substantial benefits to college enrollment and persistence. In Chicago, attending a charter school was associated with an 18.9 percentage point increase in enrolling in a four-year college, a 5 percentage point increase in attending a very selective college, and an 8.4 percentage point increase in remaining enrolled in college after four semesters.[12] In Georgia, attending a charter high school was associated with a 5.8 percentage point increase in college attendance and a 7.5 percentage point increase in college persistence.[13] In Florida, attending a charter high school is associated with about a 10 percentage point increase in attending a two- or four-year postsecondary institution, a 12.6 percentage point increase in college persistence, and an approximately $2,350 increase in annual earnings.[14]

Several studies suggest that attending a charter school yields additional long-term benefits for students and for society. A lottery study of a high-performing charter school network in New York City found that admission caused a 10 percentage point decrease in teen pregnancy and a 4.4 percentage point decrease in the likelihood of a male student being incarcerated.[15] And a study of charter schools in Charlotte, North Carolina, found that charter school attendance led to a statistically significant decrease in arrests for drug and violent felonies, yielding far less jail time for students who attended charter middle or high schools.[16]

Less Money, More Achievement

Charter schools might still be undesirable if the concentrated benefits to students enrolled came at a dispersed cost to the larger population of students “left behind” in traditional public schools. “The bottom line,” argues former vice president Joe Biden, is that charter expansion “siphons off money for our public schools, which are already in enough trouble.”[17] But is that truly the bottom line? After all, the goal of schools is not to spend but to educate.

In school districts with expanding enrollments, charter schools may provide a substantial financial benefit if charters enable districts to alleviate overcrowding without building new schools.[18] But when enrollments are stable or declining, charter expansion can create a significant financial strain on traditional school districts. As money follows students from traditional public schools to charter schools, school districts must cut costs—a difficult task for large bureaucracies governed by onerous work rules and collective bargaining requirements. Ultimately, district schools may end up shuttering.[19]

And yet—rather remarkably, given the literature showing that budget cuts tend generally to harm student achievement[20]—studies have consistently found that charter schools have positive effects on the students remaining in traditional public schools. In Arizona,[21] Michigan,[22] Florida,[23] New York,[24] Texas,[25] and North Carolina,[26] researchers have found that nearby charter school growth or launches drive positive, if modest, academic effects on student performance in traditional public schools.

Such studies may understate the positive effect if they consider only the overall effect on traditional public schools, rather than the grade levels facing direct competition. A 2014 study that did focus on direct competition found no effects in grades that did not face charter competition and larger benefits in grades that did. The author asserts that by not making any such distinction, 85% of previous studies had likely understated the benefits of charter competition.[27]

A 2018 study of spillover effects in New York City showed how charters could improve traditional public schools, despite inducing budgetary stress on the district.[28] Using teacher and parent surveys, the researcher found descriptive—though not necessarily causal—evidence that academic expectations, school safety, student and parent engagement, and communication improved in traditional public schools when charter schools opened up nearby. The study provides support for the hypothesis that being forced to compete to retain students leads to improvements in school management and pedagogy. 

The positive effects seem to build as the share of charter schools within a district increases. A 2019 study examined the effects of a higher “market share” of charter schools. It found that in large urban areas, higher charter market share is associated with significant achievement gains for black and Hispanic students district-wide.[29]

Charter schools can create a financial burden for school districts; but in doing so, they offer taxpayers a dramatically better return on investment. Charter school students often perform as well as, or better than, traditional public school students, despite receiving substantially less per-pupil funding. Researchers at the University of Arkansas conducted a cost-effectiveness analysis, measuring how many NAEP (National Assessment of Educational Progress) test-score points on reading and math each sector produced for each $1,000 per-pupil investment across eight major urban districts.[30] They found that charter schools are 36% more cost-effective in reading and 40% more cost-effective in math than traditional public schools.

Policy and Politics

One final line of evidence provides strong support for the conclusion that charter schools have a positive impact on public education and minority students: the affected families. While many politicians frame their objections in social-justice terms, polling data indicate that charter schools are strongly supported by Democrats who are black (58% in favor, 37% opposed) and Hispanic (52% vs. 30%). White Democrats, by contrast, are overwhelmingly opposed to charter schools (62%, vs. 26% who are in favor). A parallel split emerges among teachers: 50% of nonunionized public school teachers are in favor, and 37% are opposed; 71% of unionized teachers are opposed, and 28% are in favor. Republicans, for their part, remain broadly supportive (61%, vs. 27% who are opposed).[31]

Whatever has led white Democrats to abandon their support for charter schools, their conclusions are not shared by researchers or parents of color.


  1. Elizabeth Warren, “A Great Public School Education for Every Student,”
  2. Bernie Sanders, “A Thurgood Marshall Plan for Education,”
  3. Joe Biden, Democratic Public Education Forum 2020
  4. Sanders, “A Thurgood Marshall Plan for Education.”
  5. Warren, “A Great Public School Education for Every Student.”
  6. Ke Wang et al., “School Choice in the United States: 2019,” National Center for Education Statistics, U.S. Department of Education, September 2019.
  7. Center for Research on Education Outcomes (CREDO), Stanford University, “National Charter School Study,” 2013.
  8. CREDO, “Urban Charter School Study Report on 41 Regions,” 2015.
  9. Julia Chabrier, Sarah Cohodes, and Philip Oreopoulos, “What Can We Learn from Charter School Lotteries?Journal of Economic Perspectives 30, no. 3 (Summer 2016): 57–84.
  10. Will S. Dobbie and Roland G. Fryer, Jr., “Charter Schools and Labor Market Outcomes,” National Bureau of Economic Research (NBER), working paper 22502, August 2016.
  11. Do Charter Middle Schools Improve Students’ College Outcomes?” National Center for Education Evaluation and Regional Assistance, U.S. Department of Education, April 2019.
  12. Julia A. Gwynne and Paul T. Moore, “Chicago’s Charter High Schools: Organizational Features, Enrollment, School Transfers, and Student Performance,” University of Chicago Consortium on School Research, November 2017.
  13. Peter Bluestone and Nicholas Warner, “The Effects of Start-Up Charter Schools on Academic Milestones,” Georgia Center for State and Local Finance, Apr. 18, 2018.
  14. Tim R. Sass et al., “Charter High Schools’ Effects on Long-Term Attainment and Earnings,” Journal of Policy Analysis and Management 35, no. 3 (April 2016): 683–706.
  15. Will Dobbie and Roland G. Fryer, Jr., “The Medium-Term Impacts of High-Achieving Charter Schools,”  Journal of Political Economy 123, no. 5 (October 2015): 985–1037.
  16. David J. Deming, “Does School Choice Reduce Crime?Education Next 12, no. 2 (Spring 2012): 70–76. 
  17. Felicia Sonmez, “Biden Unveils Education Plan, His First Major Policy Proposal as a 2020 Candidate,” Washington Post, May 28, 2019.
  18. Matt Barnum, “Critics of Charter Schools Say They’re Hurting School Districts. Are They Right?” Chalkbeat, June 11, 2019.
  19. Robert Bifulco and Randall Reback, “Fiscal Impacts of Charter Schools: Lessons from New York,” New York State Education Department, December 2011.
  20. C. Kirabo Jackson, “Does School Spending Matter? New Literature on an Old Question,”, Winter 2018.
  21. Caroline M. Hoxby, “School Choice and School Productivity (or Could School Choice Be a Tide That Lifts All Boats?),” NBER, working paper 8873, April 2002.
  22. Ibid.
  23. Tim R. Sass, “Charter Schools and Student Achievement in Florida,” Education Finance and Policy 1, no. 1 (Winter 2006): 91–122.
  24. Sarah A. Cordes, “In Pursuit of the Common Good: The Spillover Effects of Charter Schools on Public School Students in New York City,” Education Finance and Policy 13, no. 4 (September 2018): 484–512.
  25. Kevin Booker et al., “The Effect of Charter Schools on Traditional Public School Students in Texas: Are Children Who Stay Behind Left Behind?Journal of Urban Economics 64, no. 1 (July 2008): 123–45.
  26. Robert Bifulco and Helen F. Ladd, “The Impacts of Charter Schools on Student Achievement: Evidence from North Carolina,” Education Finance and Policy 1, no. 1 (Winter 2006): 50–90; George F. Holmes, Jeff DeSimone, and Nicholas G. Rupp, “Does School Choice Increase School Quality?” NBER, working paper 9683, May 2003.
  27. Yusuke Jinnai, “Direct and Indirect Impact of Charter Schools’ Entry on Traditional Public Schools: New Evidence from North Carolina,” Economic Letters 124, no. 3 (September 2014): 452–56.
  28. Cordes, “In Pursuit of the Common Good.”
  29. David Griffith, “Rising Tide: Charter School Market Share and Student Achievement,” Thomas B. Fordham Institute, Sept. 26, 2019.
  30. Corey A. DeAngelis et al., “A Good Investment: The Updated Productivity of Public Charter Schools in Eight U.S. Cities,” School Choice Demonstration Project, University of Arkansas, April 2019.
  31. Charles Barone, Dana Laurens, and Nicholas Munyan-Penney, “A Democratic Guide to Public Charter Schools: Public Opinion,” Democrats for Education Reform, May 2019.

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