Michael Bloomberg, former mayor of New York City, announced yesterday that Bloomberg Philanthropies will spend $750 million to expand the charter school sector. Declaring that “the American public education system is tragically broken,” Bloomberg pledged to add 150,000 seats in “high-quality charter schools” over five years, with the intention of “closing the achievement gap.”

As mayor, Bloomberg had total control of the New York City public school system, which he reorganized and disrupted repeatedly. His first pick for chancellor of the schools was antitrust corporate lawyer Joel Klein, who distrusted experienced educators and turned to McKinsey and Goldman Sachs for advice. Bloomberg’s second pick for chancellor was a magazine publisher with no experience in education; she lasted just 90 days.

Bloomberg apparently decided that he couldn’t achieve sweeping change in the public schools, so he became a champion for outsourcing students to privately managed charter schools. As his press release shows, he continues to believe his own puffery. The NYC public schools continue to be plagued with crowded classrooms, while charter schools enjoy privileged status, such as co-locations inside public schools, depriving them of facilities, and rent in private spaces paid by the city.

Although the press release claims that Bloomberg’s decision is based on “evidence,” it completely ignores the large number of charter schools that close every year, the high attrition rates of charter students and teachers, and the multiple studies showing that charter schools are outperformed by public schools, except when the charters curate their enrollment to exclude students who are unlikely to succeed or conform.

One of the richest men in the world, Bloomberg loves market solutions to public problems. In his 12 years as mayor, he did not transform the public school system that he controlled. Evidently he has learned nothing about education in the eight years since he left office.

How does it help the 85-90% of students in public schools to invest in a privately run sector that, contrary to his claims, has not demonstrated success in closing the achievement gap and that poaches students and resources from public schools?

How will it “close the achievement gap” to spend $750 million to add 150,000 seats to the charter sector?