Charter co-location: A phantom threat

Mayor de Blasio has announced a moratorium on new charter school co-locations — whereby charters make use of underutilized space in public school buildings — and has said that he plans to begin charging rent to charters currently operating within publicly owned facilities.

Since empirical research makes clear that charters on average are benefiting New York City’s neediest kids, the only rational reason for de Blasio to target charters in this way is if he believes that they hurt the public schools with which they share facilities. In a new report for the Manhattan Institute, I demonstrate that this is not the case.

Rent-free co-locations have helped charter schools expand rapidly in New York City. These arrangements are necessary in part because New York State provides charter schools with no capital funds. Paying market rates for facilities out of operating revenue would be a major burden for schools looking for scarce real estate in Gotham. A recent paper by my colleague Stephen Eide demonstrated that paying rent at a rate proposed by the Independent Budget Office would have forced about 71% of charters into deficit in 2011-12.

Those familiar with public schools in New York know that co-locations are common; most, in fact, have nothing to do with charter schools. More than half of New York City’s public schools co-locate with other schools and programs. Several community-based organizations share space in public facilities. These co-locations often prompt little comment.

Nonetheless, it is worth asking whether charter school co-locations in particular are harmful to students in traditional public schools. Complaints range from fairly small issues such as insufficient closet space or changes to the building’s lunch schedule to more serious issues that could impair a school’s effectiveness, such as classroom overcrowding and the loss of classroom space used for small-group instruction and teacher preparation.

Though perhaps inconvenient, such impositions are really worrisome only if they lead to lower student performance within traditional public schools that are required to share their facilities. Thus far, no empirical research has considered whether charter school co-locations, or co-locations more generally, harm educational outcomes in traditional public schools.

To address this issue, I analyzed data on the test-score performance of New York City students over a period of five years. The data matched students to their schools and also to the building in which their school is located. I was thus able to study whether introduction of a new school within a facility, or a public school’s losing some space to another school, leads to changes in the test scores of students in the traditional public school.

I find no evidence that co-locations in New York City — whether with other traditional public schools or with charter schools — have any discernible impact on student achievement within traditional public schools. This result is consistent across various measures for the existence and magnitude of co-location.

Perhaps space-sharing arrangements produce discomfort for traditional public schools. But any inconveniences, if they exist, do not appear to manifest themselves in lower student learning within traditional public schools.

The question facing the mayor, then, is whether exposing traditional public schools to what is sometimes a mild nuisance that does not impact the achievement of their students outweighs the enormous benefits achieved by the kids attending one of the city’s co-located charter schools?

That’s an easy question to answer for anyone primarily interested in ensuring that New York’s schoolkids receive the best public education possible. It should be easy for Mayor de Blasio, too.

Winters is a senior fellow at the Manhattan Institute and an assistant professor at the University of Colorado in Colorado Springs.