Anti-school choice activists often argue that charter school expansion hurts existing schools, but a new study of New York City schools found that new charter schools are increasing the performance of schools around them.
The peer-reviewed statistical analysis, conducted by Temple University professor Sarah Cordes, indicates charter schools are not only helping the students enrolled, but also students at schools that feel pressured to increase performance due to their close proximity to a new charter school.
The study found that schools located within half a mile of a new charter school saw increased scores in both math and reading, and the increases become more significant the closer the schools were. The impact was felt most in situations where a charter school opened inside the same building as an existing school.
"The closer the school is, the more it's on the minds of the people in the building," Cordes explained to The 74, an education nonprofit.
Cordes found that the quality of the charter school does not have an impact on how much it helps other schools in the building.
"Just the presence of an alternative does it," she said. "It doesn't really matter how great that alternative is—it's just the fact that that alternative is there, it's in the building, and people see it every day."
Cordes's study, which looked at 900,000 children in grades three through five who attended a public school within a mile of a charter school, found that schools sharing buildings with charters saw upticks in student attendance and far less students failing to advance to the next grade.
There were also marked improvements in student safety and school cleanliness.
Cordes credits competition for most of the improvements, but she also notes that spending per student increased at the existing schools due to drops in enrollment.
Schools within half a mile of charters saw a nearly 5 percent increase in spending per student after the charter was introduced.
New York City mayor Bill de Blasio has fought to restrict the expansion of charter schools, arguing that his focus will remain on improving the city's traditional public schools.
De Blasio, however, was forced to agree to a charter school expansion in exchange for control over the city's public schools for another two years.
Cordes says she was surprised by the results of her research given the conventional wisdom on the impact of charter schools. "So much of the talk about co-location is so negative, I was somewhat surprised to see the effect was as positive as it is," she said. "I really went into this not knowing what I would find."
The report explains that further research is required to determine exactly what is causing the increased performance in public schools, and also to see whether the results are similar in other large cities.