San Antonio is set for a major expansion of privately managed charter schools. Several national chains will open there, welcomed by the mayor and the business community. The San Antonio Express News published an opinion column by an advocate for the corporate charter chains, but refused to print Professor Julian Vasquez Heilig’s succinct rebuttal.

Despite the blue-sky promises of the charter industry, Heilig writes, the vast majority of Latino and African-American students are prepared for college in public schools. The Stanford CREDO study showed that charters in Texas underperform the state’s public schools. Don’t believe the tales of 100% graduation rates and 100% college-admission rates, he warns. They mask high attrition rates.

For example:

“Same story with BASIS. At the original campus of BASIS charter school in Tucson, Ariz., the class of 2012 had 97 students when they were 6th graders. By the time those students were seniors, their numbers had dwindled to 33, a drop of 66 percent.

“So what happens to families who get churned out of charters like KIPP and BASIS? They end up back at their neighborhood public schools, who welcome them with open arms as they do all students, regardless of race, class, circumstance or level of ability.”

Why not tell the truth about charters? They do not accept the same students. They have high attrition rates. When they enroll the same students, they get the same results, so they get rid of low-performing students. It works for some kids, who can attend a schol where there are few if any kids with disabilities, English learners, or troublemakers. But it creates a dual system that harms public education.