New York City’s charter schools benefit neighborhood public schools, concludes a study by Marcus Winters, senior fellow at the Manhattan Institute.
. . . for every 1 percent of public school students who leave for a charter, reading proficiency among those who remain increases by about 0.02 standard deviations. Math performance is unaffected. However, the lowest-performing students in a school benefit from charter-school competition in both math and reading.
Competition from charter schools pushes the local school to improve instruction for the remaining students, Winters suggests.