Michael Mulgrew is president of New York City’s United Federation of Teachers, the largest local in the nation and in the American Federation of Teachers.

He published this article in the New York Daily News, which is strongly pro-charter and often writes about the “success” of the city’s charter schools compared to its public schools. Mulgrew explains here the secrets of charter “success.”

The research behind his article is here. 

Careful selection, exclusion, and attrition are keys to charter success.

Mulgrew writes:

Cheerleaders for New York City’s charter school sector typically trumpet the academic achievements of charter school students.

But there is an inconvenient truth about these schools that charter supporters rarely discuss, or even admit. The schools’ “success” is due not to any superior instructional strategy but rather to segregation — segregation based on students’ academic and social needs.

Though charters are open to all by lottery, as a group they enroll a significantly smaller percentage than public schools of our neediest children, such as English language learners, special education students or those from the poorest families. Children like these typically have the largest learning challenges.

For the 2018-19 school year, for example, the latest for which data is available, charters as a group enrolled half the citywide average of ELLs (6.9% vs. a citywide average of 14.6%) and a third of the special education students with the highest level of need (1.7% vs. a citywide average of 5.4%).

But the charter sector average turns out to be only half the story. An analysis of individual charter schools clearly shows that the schools most successful at excluding these kinds of students turn out to be — no surprise — the charters with the highest test scores.

As measured by the most recent state English language exam, the most academically successful charters (those with a pass rate of 67% or higher) had even fewer English Language Learners and special ed students.

That’s not a bug in the charter world; it’s a feature. Throughout the charter sector, as the number of children with academic and other needs grows, the average proficiency rate on the state test declines, to the point that the nearly 50 charters with the highest percentages of needy children don’t even reach the citywide average on the state reading exam.

How do many charters — particularly those most successful on standardized tests — find ways to minimize the number of pupils unlikely to contribute to that success?

They start with highly committed families, those with a knowledge of the system and the motivation to enter their children in the charter lottery.

Robert Pondiscio, who has many sympathies for charters, wrote most recently that the idea that essentially the same kinds of students attend both public schools and charters, while “deeply satisfying to charter school advocates…is also misleading and even false” because of the critical nature of this parental motivation.

The next step in the charter success strategy is to find ways to ease out kids less likely to be successful. A key tactic is using suspensions to persuade students who do not fit well to find other schools.

Our analysis shows that less academically successful charters actually gained students over time. However, the most academically successful charters also showed significant attrition — a loss of more than one-quarter of the pupils who started in the cohort that began in 2010.

Were all those pupils who left the top charters academic stars? Or, as is much more likely, are the top charters consciously shedding weaker students and reaping the benefits in terms of higher test scores?

State data shows that charters as a group suspended students far more frequently than public schools did, and that the top charters — with a suspension rate of more than 8% — led the way.

Public school students in more than 100 schools have given up labs, libraries, music rooms and other facilities to charters that have been co-located in their buildings.

The bill for charters continues to grow. Some $2.4 billion in city Department of Education funds will be diverted in the coming fiscal year to charter operations, and current charters, even with no further regulatory or legislative action, are scheduled to expand their grades in future years.

Enormous public investments are going to too many schools that fail to educate the neediest students, and then rely on such exclusion to fuel their claims of success.