The research for the stories was funded through the non-profit Hechinger Institute , which sponsors investigative journalism on education issues and is directed  by a former fellow at the pro-charter Hoover Institution at Stanford — which makes the stories’ critical conclusions about this issue even more striking. Parents and students explained to the reporters how charter staff openly recommended that they transfer back into public schools or required them to pay hundreds of dollars to the school for the students’ disciplinary infractions.
As the reporter for WBEZ notes, Chicago school chief Ron Huberman dismissed such stories as a “myth,” but then failed to provide an evidence for his claims:
Schools chief Ron Huberman says when charters are successful it’s thanks to rigorous curricula, and motivated teachers who spend more time with students. He doesn’t believe charters have policies that systematically weed out weaker students.
HUBERMAN: I have found none of that to be true. What I have found is that it is a promulgation of a myth.
Huberman said he’d turn over data to support his finding, but the district didn’t keep that promise. WBEZ did obtain an internal CPS memo. It’s titled “Memorandum on Charter School Myths.” The four-page report actually finds that traditional schools held onto more kids than charters did for the year CPS examined. It found that both charters and traditional schools lost lower-performing students.”
As well-researched as these stories are, one of the key points they don’t mention is that unlike district schools, charters aren’t required to replace the students who leave, further skewing their test scores upward. After a similarly critical report  on high attrition in Boston charter schools came out earlier this year, Massachusetts revised  its charter regulations  to require new charters to replace students in certain grades (for example, some 6th-12th grade charters now need to admit new students in 9th grade).
Based on recent data , New York City’s charters also experience high student attrition — especially in some of the city’s highest achieving middle schools, such as KIPP and Harlem Village. As the state’s authorizers begin the process of approving and renewing hundreds of charters over the next five years, perhaps student attrition is something they should consider more seriously and systematically in deciding which schools should be considered successful.