Book excerpt: In dozens of places in New York City where a charter school and a traditional public school hold classes in the same building, charter school students in those buildings have achieved "proficiency" on statewide tests several times more often than traditional public school students taking the same tests. In 2013, a fifth-grade class in a Harlem charter school scored higher on a mathematics test than any other fifth-grade class in the entire state of New York. That included, as the New York Times put it, "even their counterparts in the whitest and richest suburbs, Scarsdale and Briarcliff Manor." Nationwide, charter schools have only a fraction of the number of students who attend traditional public schools. But charter schools enrollment is growing faster, especially in low-income minority communities. From 2001 to 2016, enrollment in traditional public schools rose 1 percent, while charter school enrollment rose 571 percent. In cities across the country, with many students on waiting lists to transfer into charter schools, public school officials are blocking charter schools from using school buildings that have been vacant for years, in order to prevent those transfers from taking place. Even in states where blocking charter schools from using vacant school buildings is illegal, the laws have been evaded. In some places, vacant school buildings have been demolished, making sure no charter schools can use them. Book jacket.