Thousands have been shuttered since the turn of the century. More than 35 percent of those given federal grant money between 2006 and 2014 either never opened or were shut down, costing taxpayers more than half a billion dollars. Nearly 91 percent have failed in Iowa—in Virginia, 71 percent.

No, these figures aren’t about start-up companies trying to become the next Uber. They’re from a new report by the Network for Public Education, which reveals staggering data about the U.S. Department of Education’s Charter Schools Program (CSP).

At least $504 million of the more than $4.1 billion dollars the CSP has spent to fund new charter schools and expand existing charter schools was wasted on defunct schools.

This adds to the bevy of data showing that charter schools are more volatile and disruptive than traditional, neighborhood public schools that, if given adequate funding, can help hold communities together. Students at charter schools are two and a half times more likely to have their school close than those at neighborhood schools.

To the likes of billionaire Education Secretary Betsy DeVos—who calls public education an “industry”—constant churn is a good thing. She’s compared charter schools to food trucks and—you guessed it—the rideshare companies Uber and Lyft.

The deep-pocketed voices aiming to privatize public education are fine with a system that creates winners and losers—in fact, that’s exactly what they want.

But the data overwhelmingly show that school closures harm students. They often damage relationships students have with friends and others. They can end long-standing parent and teacher relationships. They appear to slightly lower test scores. They can increase student absenteeism. They can destabilize families who can’t afford higher transportation costs. Further research is needed on the psychological effects of closures, but they also likely provoke feelings of grief and loss.

Get this: this past October, a charter school in California’s Central Valley unraveled over the course of a month, abruptly closing its doors in the middle of the school year. Its students have since scrambled to find other options, swelling the class sizes of the local school district.

As the Network for Public Education says, the federal government is “asleep at the wheel” when it comes to bankrolling failing charter schools. Public money should be spent to benefit students, not charter school entrepreneurs.

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