The News and Observer editorial board in North Carolina published a sharp critique of the state voucher program and a very flawed study of it.

The state gives a voucher worth $4,200 per student. The students who get vouchers do not take the state’s standardized tests. A recent “study” claimed that they were making progress, but the voucher schools and public schools don’t take the same tests, and the students in the study were not representative of the program.

“Two researchers from N.C. State’s College of Education and a third from the Friday Institute for Educational Innovation at N.C. State set out to explore this yawning accountability gap in the nation’s least regulated voucher program. They recruited 698 student volunteers in grades 4 through 8 from public and private schools to take the Iowa Test of Basic Skills in the spring of 2017. After students were sorted and some eliminated by various factors, the final comparison involved 245 students in private school and 252 in public schools. More than 7,000 students received Opportunity Scholarships in the 2017-18 school year.

“The students getting Opportunity Scholarships showed a “positive, large and statistically significant” edge on the exams, the researchers said. But that conclusion came with multiple caveats. For one, half the private school students were from Catholic schools, which represent only 10 percent of the more than 400 schools receiving vouchers. In addition, the researchers stressed how a lack of common testing requirements for public schools and voucher-receiving private schools limits the applicability of their findings.”

Most of the students in the voucher program attend evangelical Christian schools, which typically use textbooks that deny evolution and teach bigotry and invalid history based on the Bible.

Voucher proponents are cheering the results. The program is budgeted to grow by $10 million per year until 2028, when it will cost $145 million annually.

“The law creating the program contains virtually no requirements that private schools receiving public dollars account for the quality of their curricula or the performance of their students. That is in sharp contrast to Republican lawmakers’ enthusiasm for tying public school teachers’ salaries to student performance and slapping letter grades on every public school based on test results…

“We still haven’t measured the impact of vouchers. And we still don’t know if they work.”