School choice opponents frequently claim the Washington, D.C., school voucher program is a failure. But I have a hunch that’s going to change pretty soon.

The previous federal evaluation of the D.C. Opportunity Scholarship Program found negative effects on math test scores and no effects on reading test scores after two years. But the most recent evaluation , just released Wednesday, found that winning a lottery to use a voucher to attend a private school in D.C. had no effects on math or reading test scores after three years.

Though seemingly lackluster, these results are actually great news for school choice.

Public schools in D.C. spend around $28,000 per student each year, while the average private school voucher amount is only around $9,600 per student each year in D.C.. That means a K-12 education costs around $364,000 for each child in D.C. public schools, but only about $125,000 for each voucher student.

That’s right — the federal evaluation reveals that private schools produce the same academic outcomes for only a third of the cost of the public schools. In other words, school choice is a great investment.

But that’s not all.

This study adds to the mounting evidence that school vouchers are tickets to safer schools . Students that won the voucher lottery to attend a private school were 34% more likely to report being in a very safe school than their peers in public schools. While students using vouchers took three years to catch up to their public school peers on math test scores, the federal evaluation found positive safety effects every year. Two other experimental evaluations have similarly found that school vouchers improve school safety.

The D.C. voucher program also increased students’ satisfaction with their schools by 18% and decreased chronic absenteeism by 27% after three years. Imagine that: When a student is satisfied with their school, and they feel safe while they’re there, they are more likely to show up to class each day.

But how do private schools compete with D.C. public schools with a third of the funding per student?

It’s pretty simple. Basic economic theory suggests we shouldn’t be surprised that private schools do more with less. Private schools must cater to the needs of their customers (families) if they want to keep their doors open. Public schools, on the other hand, hold strong monopoly power because of residential assignment and funding through property taxes.

The most recent federal evaluation of the D.C. voucher program finds that it increases student satisfaction and safety, and decreases absenteeism, at a third of the cost of public schools. That’s obviously a great investment. But why do students receive a third of the funding for simply choosing a school that works for them? And what kinds of benefits would the program produce if all students were equitably funded?

Corey DeAngelis is Director of School Choice at the Reason Foundation and an adjunct scholar at the Cato Institute.